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Dynamic Development of Action and Thought
Chapter in Journal of Sport & Exercise Psychology � May 2007
Impact Factor: 2.59 � DOI: 10.1002/9780470147658.chpsy0107
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313
CHAPTER 7
Dynamic Development of Action and Thought
KURT W. FISCHER and THOMAS R. BIDELL
DYNAMIC STRUCTURALISM 314
Variability in the Middle of Things: An Example of
Representing Social Interactions 315
Dynamic Nature of Psychological Structure 317
Dynamic Structure in Living Systems 318
Variation and Order in Development: The
Constructive Web 319
DYNAMIC STRUCTURE IN COGNITIVE AND
EMOTIONAL DEVELOPMENT 320
Psychological Structure as Dynamic Skill 321
Building a Constructive Web for Positive and Negative
Social Interactions 325
How Dynamic Skills Explain Variability
in Development 329
THE CRISIS OF VARIABILITY AND THE
CARTESIAN SYNTHESIS IN
DEVELOPMENTAL SCIENCE 336
The Cartesian Dualist Framework 337
The Tacit Modern Synthesis in Psychology: Nativism and
Empiricism Together 338
The Structure-as-Form Paradigm 340
The Stage Debate and the Discovery of Variability in
Cognitive Development 341
Explaining Variability versus Explaining It Away 342
The Constructivist Alternative 346
METHODOLOGY OF DYNAMIC
STRUCTURAL ANALYSIS 347
Starting in the Middle of Things: Implications
for Design 348
Guidelines for Developmental Research 349
Building and Testing Models of Growth
and Development 356
BUILDING STRUCTURES: TRANSITION
MECHANISMS, MICRODEVELOPMENT, AND
NEW KNOWLEDGE 363
Relations between Micro- and Macrodevelopment 363
Construction Processes: From Micro to Macro 364
EMOTIONS AND THE DYNAMIC ORGANIZATION
OF ACTIVITY AND DEVELOPMENT 370
Emotion and Cognition Together 370
Organizing Effects of Emotions 372
Emotionally Organized Development 376
JOINING NATURE AND NURTURE: GROWTH
CYCLES OF PSYCHOLOGICAL AND
BRAIN ACTIVITY 382
Epigenesis of Action, Feeling, Thought, and Brain 382
Principles for Understanding Growth Patterns of Brain
and Behavior 383
Cycles of Reorganization in Development 385
CONCLUSION: DYNAMICS OF STABILITY AND
VARIABILITY IN DEVELOPMENT 388
REFERENCES 390
Human activity is both organized and variable, dynami-
cally changing in principled ways. Children and adults
are flexible and inventive in their action and thought,
adapting old ideas to new situations and inventing con-
cepts, formulating plans, and constructing hypotheses
while participating in a wide variety of cultural prac-
tices. Few developmentalists today would disagree, as, for
half a century, psychologists have been accumulating a
Preparation of this chapter was supported by grants from Ms.
and Mrs. Frederick P. Rose and the Harvard Graduate School
of Education.
wealth of evidence on the constructive, self-regulating,
and culturally contextualized nature of human psycholog-
ical processes. If psychological function—the way people
act—is constructive, dynamic, and culturally embedded,
then psychological structure—the organization or pattern
of activities—is equally so. Yet remarkably, the most
widely used conceptions of psychological structure and
its development do not reflect this dynamic, constructive,
and contextualized picture of psychological processes.
The opposite is true: The major models of development
describe psychological structure in static, formal terms.
Concepts like universal stages, innate linguistic modules,
and innate cognitive competencies portray psychological

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314 Dynamic Development of Action and Thought
organization as fixed and unchanging, insulated from
variation in context and feedback from activity.
The hallmark of the dynamic nature of human behav-
ior is its pervasive variability: People act differently in
different situations, with different people, in different
emotional states. Faced with the large and growing cor-
pus of research evidence for variability in activity and
development, researchers guided by static models have
been continually surprised to find that children’s
performance is nowhere near as stable as the static con-
ceptions predict. A child who can solve an arithmetic
problem (or a social problem) one day or in one situation
frequently cannot solve the same problem the next day or
in a different but apparently similar situation. Different
children of precisely the same age often cannot perform
the same cognitive tasks—sometimes in relation to cul-
tural contexts or family environment, sometimes for rea-
sons that are harder to explain. Even from moment to
moment, a person performs a task differently as she or
he adapts to variations in the situation, social context, or
emotions of self and others. Indeed, when the data of
cognitive developmental research is taken as a whole,
variability in the level of psychological performance is
the norm, not the exception.
The task of developmental science is to detect and de-
scribe patterns in this variability and to propose models
to account for data patterns that reflect both stability
and variability. We show how the concepts and methods
of dynamic structural analysis provide a framework and
tools for analyzing this variability and detecting the
order in it—key findings such as the emergence of qual-
itatively new cognitive abilities or the transitions from
one behavior to another.
In our view, performances vary so greatly because
psychological structure is not static but naturally pro-
duces variability in activity and development arising
from people’s constructive self-organization of their
own psychological structures in relation to situations,
other people, meaning systems, and their own bodies.
Far from being a problem, patterns of developmental
variability are the key to understanding the organiza-
tion of these dynamic systems and the constructive
processes by which human agents create new interrela-
tions and thus new structures. The complexity of these
systems is not something to be controlled for but to be
described and understood. The patterns of variability
that arise from the particular ways in which cognitive
systems are organized are the key to understanding that
organization and thus to understanding psychological
structure. Tools from dynamic systems analysis pro-
vide ways of embracing the variability to find the order
in it.
With this chapter, we present a framework for con-
ceptualizing psychological structure in dynamic sys-
tems constructed by human agents. We show how
this model describes and explains patterns of develop-
mental variability in terms of the structures human be-
ings build. The chapter begins with an introductory
overview of dynamic structuralism as a general ap-
proach to development, elaborating a theoretical model
of psychological structure as the dynamic organization
of self-constructed, socially embedded skills and ac-
tivities (actions and thoughts). We contrast this posi-
tion with traditional static views of psychological
structure, which dominate scientific dialogue in what
amounts to a modern synthesis of traditionally opposed
viewpoints of nativism and empiricism. These static
views derive from reductionist scientific theory inher-
ited from the Cartesian tradition in philosophy, which
leads to systematic misunderstanding of the nature of
psychological structure and blatant failures to explain
the extent of developmental variability.
The dynamic framework and research tools specifi-
cally crafted for analyzing development and learning
provide a research methodology for the study of psycho-
logical structures including both their variability and
the order in the variation. These concepts and tools
apply to both long-term development and short-term mi-
crodevelopmental variations in the building of dynamic
structures, providing powerful methods for testing dy-
namic hypotheses about variation, change, and stability.
Broad in scope and applicability, the dynamic structural
model and methodology elucidate relations between
cognitive, social, emotional, and neurological develop-
ment—which all work together in the activities of
human beings in all their rich complexity.
DYNAMIC STRUCTURALISM
One reason psychological structure has so often been
treated as static is that theorists have confounded struc-
ture with form. Structure refers to the system of relations
(Piaget, 1970) by which complex entities such as biologi-
cal organisms and psychological activities are organized.
There are systematic relations, for instance, between the
nervous system and the cardiovascular system such that
each supports and responds to the other. The relations
between these systems are in a constant balance or equi-

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Dynamic Structuralism 315
librium, which can only be maintained by constant activ-
ity on the part of each subsystem. Thus, systems of rela-
tions—structures—are necessarily dynamic.
Form is an abstraction from structure—a fixed pat-
tern that can be detected in a dynamic structure. An or-
ange has cellular and tissue-level structure, which lead
to its cohesion in a spherical shape. The structure of the
orange is dynamic, emerging developmentally, maintain-
ing a dynamic equilibrium for a time, and then decaying.
The concept of sphere, on the other hand, is an abstract
form that we apply to describe one characteristic of the
dynamic structure: the shape it produces. Beyond the or-
ange, the concept of sphere is an ideal form that applies
across myriad realities. The fact that this formal con-
cept is unchanging across many situations is what makes
it useful in describing similarities in many different ob-
jects such as balls, plums, or planets.
A structure/form problem arises when an abstrac-
tion used to describe reality is confounded with the re-
ality described. People commonly expect patterns of
phenomena in the world to conform to their underlying
abstractions, instead of determining which patterns fit
an actual object or experience. In personality and so-
cial relations, people commonly expect others to fit the
stereotype of, for example, a shy, introverted person or
a mother (Greenwald et al., 2002). Similarly, in sci-
ence, researchers who focus on the sphere form may be
surprised that baseballs, basketballs, and soccer balls
are so different from one another, and researchers who
focus on innate knowledge may be surprised to find
that a 3-year-old really does not understand the num-
bers 1, 2, and 3 even though an infant can distinguish
arrays of 1, 2, and 3 dots (Spelke, in press). For the
sphere, the logical fallacy is obvious: The spherical
shape is an abstraction of a common pattern across dif-
ferent objects, not an independently existing form that
somehow dictates what the objects should be like. The
same fallacy applies to the stereotypes and the nativist
explanation of number.
This form fallacy has frequently led to perplexity
among scientists and educators who expect patterns of
thought and action to conform to an independently exist-
ing form such as stage, cognitive competence, or core
knowledge. Scholars have been puzzled when a child
reaches a certain stage or competence for one task or sit-
uation and he or she does not evidence the same ability
in other tasks or situations, as if an underlying abstract
logic could determine an individual’s performance in
the real world (Piaget, 1985). The attempt to preserve
formal conceptions of structure in the face of ever grow-
ing evidence of variability in cognitive performance has
led developmental theorists into pointless arguments
over, for example, which of many varying performances
represent an individual’s “real” logical ability, or at
what age children “really” acquire a concept like object
permanence. We demonstrate later how the confounding
of form with structure has led to an explanatory crisis in
developmental science with ever more tortured attempts
to explain the pervasive evidence of variability in static
conceptions of structure as form. (We also see hopeful
signs that the field is shifting to deal more centrally
with the dynamics of variation.)
Dynamic structuralism offers an alternative to static
conceptions of structure, starting with the recognition
of the complexity inherent in human psychological de-
velopment and the central role of the person in con-
structing dynamic systems of action and thought.
Instead of trying to eliminate or get beyond the com-
plexity of relations among systems, dynamic structural-
ism uses the tools of contemporary developmental
science to analyze patterns in the complexity—how the
constructive activity of human agents leads to new rela-
tions among systems of action and thought. The analysis
of the dynamic structures of human behavior provides a
way of simplifying without discarding complexity, iden-
tifying the essential relations among systems, and ex-
plaining activities and developmental pathways in terms
of those essential system relations. Dynamic structural-
ism thus differs from the classic structuralism of Piaget
(1983), Chomsky (1995), and others, which isolates
structure from the variability of mental dynamics, treats
it as static, and attempts to explain development in
terms of the static forms.
Variability in the Middle of Things: An
Example of Representing Social Interactions
Focusing on the pervasive variability of human activity,
dynamic structuralism analyzes the patterns of stability
and order in diverse patterns of activity in the variation
(Bidell & Fischer, 1992; Fischer, Yan, & Stewart, 2003;
Siegler, Chapter 11, this Handbook, Volume 2; Thelen &
Smith, Chapter 6, this Handbook, this volume; van
Geert, 1998). As in the study of ecology, the analysis
begins in medias res, in the middle of things. Starting in
the middle of things means that people’s activities are
embodied, contextualized, and socially situated—un-
derstood in their ecology (Bronfenbrenner & Morris,

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316 Dynamic Development of Action and Thought
Chapter 14, this Handbook, this volume; Cairns, 1979;
Gibson, 1979) as well as their structure. People act and
understand through their bodies acting in the world, not
through a disembodied mind or brain. The brain and
nervous system always function through a person’s body
and through specific contexts composed of particular
people, objects, and events, which afford and support
the actions. People act jointly with other people within
culturally defined social situations, in which activities
are given meaning through cultural frames for interpre-
tation (Rogoff, 1990). Action in context is the center of
who people are and how they develop (Lerner & Busch-
Rossnagel, 1981; Brandtst�dter, Chapter 10, this Hand-
book, this volume).
Starting in the middle of things with embodied, con-
textualized, socially situated individual and joint activ-
ity requires two major steps: (1) to describe basic
structures or organizations of activities in context and
(2) to characterize how those structures vary as a func-
tion of changes in key dimensions of person, body, task,
context, and culture. Whether the focus is on knowl-
edge, action, emotion, social interaction, brain function-
ing, or some combination, the dynamic structural
approach puts the person in the middle of things and
frames the person’s activity in terms of multiple compo-
nents working together. The maturity or complexity of
people’s behavior varies widely and systematically from
moment to moment and across contexts, states, and in-
terpretations or meanings. Each individual shows such
variations, in addition to the wide variations that occur
across ages, cultures, and social groups.
Consider, for example, the wide variation docu-
mented for children’s stories or narratives about posi-
tive and negative social interactions (Fischer & Ayoub,
1994; Hencke, 1996; Rappolt-Schlichtman & Ayoub, in
press; Raya, 1996). The developmental level, content,
and emotional valence of a child’s stories vary dramati-
cally as a function of priming and immediate social sup-
port, emotional state, and cultural experience. For
example, the activities of 5-year-old Susan demonstrate
some of the variations in both developmental complexity
and emotional organization that have been documented
in research. First, she watches her counselor act out a
pretend story with dolls: A child doll named after Susan
makes a drawing of her family and gives it to her father,
who is playing with her. “Daddy, here’s a present for
you. I love you.” Then the daddy doll hugs the girl doll
and says, “I love you too, and thanks for the pretty pic-
ture.” He gives her a toy and says, “Here’s a present for
you too, Susan.” When asked, the girl promptly acts out
a similar story of positive social reciprocity, making
Daddy be nice to Susan because she was nice to him.
Ten minutes later, the counselor asks the girl to show
the best story she can about people being nice to each
other, like the one she did before. Instead of producing
the complex story she did earlier, she acts out a much
simpler story, making the Daddy doll simply give lots of
presents to the child doll, with no reciprocal interaction
between them. There is no social reciprocity in the story
but only a simple social category of nice action.
A few minutes after that, when the girl has sponta-
neously shifted to playing at fighting, the counselor
shows her another nice story about father and child. This
time, when the girl acts out her story, she switches the
content from positive to negative with energetic aggres-
sion. The girl doll hits the Daddy doll, and then he yells
at her, “Don’t you hit me,” slaps her in the face and
pushes her across the room, showing the violence that
often appears in the stories of maltreated children. The
girl doll cries and says she is scared of being hit again.
Note that, despite the shift to negative affect, Susan sus-
tains a story involving social reciprocity: The Daddy
doll hits the Susan doll because she had hit him, and she
becomes afraid because he had hit her.
Then Susan becomes agitated; yelling, she runs
around the room and throws toys. When the counselor
asks her to do another story, she makes the dolls hit and
push each other with no clear reciprocity and no expla-
nation of what is happening. With her distress and disor-
ganization, she no longer acts out a complex aggression
story but is limited to stories of repeated hitting, even
when she is asked to produce the best story she can. She
uses a simple social category of mean action.
What is the “real” story for the child? Does she rep-
resent relationships between fathers and daughters as
positive or negative? Is she capable of representing reci-
procity, or is she not? These are the kinds of questions
that are often asked in child development, but these
questions assume an opposition that makes no sense.
Susan plainly shows four different “competences”—
positive reciprocity, positive social category (without
reciprocity), negative reciprocity, and negative social
category. Depending on the immediate situation, her
emotional state, and the social support from her coun-
selor, she demonstrates each of these four different
“abilities.” Her four skills vary strongly in both emo-
tional valence and developmental level (complexity)
with the different skills linked to the social context, her
emotional state, and her relationship with her father and
her counselor.

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Dynamic Structuralism 317
Figure 7.1 Variation in competence for stories as a function
of social-contextual support. In the high-support assessments
the interviewer either modeled a story to a child (Elicited Imi-
tation) or described the gist of a story as well as some content
cues (Prompt), and then the child acted out or told a similar
story. In the low-support assessments the interviewer provided
no such support but either asked for the best story the child
could produce (Best Story) or let the child make up a number
of stories in free play with the most complex story determining
the child’s “competence” for this context (Free Play). Children
had performed similar stories several times before the assess-
ments graphed here. The y-axis indicates steps in the assessed
developmental sequence, as well as skill levels (Rp1 to Rp3),
which will be explained later. Sources: From “The Dynamics
of Competence: How Context Contributes Directly to Skill”
(pp. 93–117), by K. W. Fischer, D. H. Bullock, E. J. Rotenberg,
and P. Raya, in Development in Context: Acting and Thinking
in Specific Environments—The Jean Piaget Symposium Series,
R. H. Wozniak & K. W. Fischer (Eds.), 1993, Hillsdale, NJ:
Erlbaum; and “The Effects of Development, Self-Instruction,
and Environmental Structure on Understanding Social Interac-
tions,” by E. J. Rotenberg, 1988, Dissertation Abstracts Inter-
national, 49(11), p. 5044B.
Low Support
Condition
Elicited Imitation
Free Play
Best Story
Prompt
Free Play
Best Story
1
0
2
3
4
5
6
7
Rp2
Rp1
Rp3
High
Support
Low Support
High
Support
Highest Step/Level
Different contexts for assessment routinely produce
such substantial variations, although most developmen-
tal theories and methods do not deal with this variabil-
ity. Children (and adults) show distinct levels of
competence under different conditions, even for a single
domain such as stories about nice and mean social inter-
actions between peers (A. Brown & Reeve, 1987; Fis-
cher, Bullock, Rotenberg, & Raya, 1993). Figure 7.1
shows the best (most complex) performances of eight 7-
year-old children who were acting in (a) several contexts
in which an interviewer provided high social support for
complex stories, such as prompting the gist of the plot,
and (b) several contexts providing no such support. As
the context shifted, the children’s competence for repre-
senting mean, nice, or nice-and-mean social interactions
shifted dramatically and systematically. Every individ-
ual child showed a similar pattern of shifting across con-
ditions—competence at step 6 or 7 for high-support
conditions, and competence at step 2, 3, or 4 for low-
support conditions. This variation is an example of de-
velopmental range, the spread between competence with
high support and competence with little support. With
both positive and negative stories, Susan demonstrated a
developmental range varying from interactions with so-
cial reciprocity to interactions based on a single, non-
reciprocal category. For example, she showed a higher
competence of social reciprocity when the interviewer
first demonstrated a story of nice reciprocity for her and
a lower competence of nonreciprocal social interaction
when she later made up a story without the interviewer’s
demonstration. Labeling her as having or understanding
social reciprocity misrepresents the range of her compe-
tence, as does labeling her as having only a nonrecipro-
cal social category.
Depending on their emotional state, children also
show different emotional valences in their representa-
tions, just as Susan did in her shift to negative stories.
Maltreated children often shift the content of stories
from positive to negative, and, when they become agi-
tated, the sophistication of their negative stories deteri-
orates and remains low until they become calmer
(Ayoub & Fischer, in press; Buchsbaum, Toth, Clyman,
Cicchetti, & Emde, 1992).
These kinds of variations need to be center stage and
the focus of developmental analysis. Only by including
these variations as a function of context, culture, state,
and other key contributors to behavior can scholars build
an effective framework for explaining the many shapes
of human development. Dynamic structuralism provides
concepts and tools for founding developmental explana-
tion and description of these variations, and it encour-
ages the building of theory and method that capture the
rich complexity that is the legacy of the human species.
Dynamic Nature of Psychological Structure
What is psychological structure? Why is it important in
explanations of development? The answers depend on
assumptions about the nature of the mind and its rela-
tion to other biological, psychological, and social phe-
nomena. Psychological structure is the organizational
property of dynamic systems of activity, and analysis
of dynamic structure starts with assumptions that are
fundamentally different from the traditional view of

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318 Dynamic Development of Action and Thought
structure as static form. The concept of structure in
stage theory and related viewpoints equates form with
structure and thus founders on the “discovery” of vari-
ability in development (as do most other traditional
psychological concepts). The continued dominance of
the structure-as-form paradigm has prevented an ade-
quate resolution of the crisis of variability in develop-
mental theory.
To build successful models of dynamic psychological
structure, it is essential to understand how dynamic
structure differs from static form. An essential first
step is to focus simultaneously on variability and stabil-
ity. Indeed, the neglect of variability helps ensure that
models remain static, missing the sources of order in the
variation and treating structures as static forms. Any
adequate account of psychological structure must ex-
plain not only the stability that allows systems to func-
tion and maintain themselves over time and space but
also the wide variability that arises from the dynamics
of self-organizing systems. Models of psychological
structure must specify mechanisms by which activities
are organized dynamically in relation to multiple influ-
ences that are biological, psychological, and social.
In this section, we illustrate how a dynamic struc-
tural framework deals with variability and stability si-
multaneously and thus introduces powerful explanations
of development, including cognition, social interaction,
emotions, and even brain development.
Dynamic Structure in Living Systems
All living systems—whether biological, psychological,
or social—must be organized to function. A living or-
ganism that becomes sufficiently disorganized dies. A
disorganized society collapses. A disorganized mind
leaves a person helpless in the face of everyday prob-
lems. This organizational aspect of living systems is
what we call structure, a dynamic patterning and relat-
ing of components that sustain the organized activities
that define life and living things.
To say that a system is structured or organized im-
plies that specific relations exist among its parts, sub-
systems, or processes. In the human body, for example,
the respiratory, circulatory, digestive, metabolic, and
nervous systems must all function in very specific rela-
tions to maintain the overall functioning and health of
the organism. Similarly in a complex society, the eco-
nomic system, judiciary, political/electoral system, and
government must maintain specific relationships to sus-
tain the society. In this way, dynamic structure exists
only where relationship exists, and relations among the
parts of a system provide its specific organization.
To flourish, living systems must be more than just or-
ganized. They must be dynamic. Systems must con-
stantly move and change if they are to carry out their
functions and maintain their integrity and their interre-
lations with other functioning systems. A system that
becomes static—unable to change and adapt to varying
conditions—will quickly perish. Social, psychological,
or biological systems must be able to stretch the limits
of their current patterns of organization, and even to ac-
tively guide and reorganize the relations that constitute
their structure. An organism or society that becomes in-
flexible and incapable of adaptive response to variations
in its environment will die as surely as one that becomes
disorganized. Thus, structure must be distinguished not
only from disorganization but also from static form,
which really is the antithesis of structure. Structure is
fundamentally dynamic because it is a property of liv-
ing, changing, adapting systems. Susan demonstrated
this dynamic adaptation in her variable representations
of social interactions with her father and counselor. Dy-
namic variation is a fundamental property of human ac-
tion and thought.
The human mind is a specialized living system that
participates in and with other bodily, environmental,
and social systems. The specialized function of the
human mind is to guide and interpret human activity in
relation to the world of people and objects. The activity
takes places in medias res, in the middle of things, not in
the person alone or in the brain. The objects and people
in the physical and social world of the actor are actually
part of the activity.
Moreover, living systems are agentive—self-regulating
and self-organizing, adapting and changing as a conse-
quence of goal-oriented activity, as in Susan’s activities
(Bullock, Grossberg, & Guenther, 1993; G. Gottlieb,
2001; Kauffman, 1996). In seeking its goals, a living sys-
tem is involved in multiple relations with other living
and nonliving systems, and they are part of one another’s
dynamics.
This agency and interaction lead naturally to variabil-
ity in systems. If systems were static, they would be un-
changing; but because they move and change, they give
rise to patterns of variability. The more complex a sys-
tem, the more relations are entailed by its structure and
the greater the variability it is likely to display. Human
beings show more variability in activity than lizards,

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Dynamic Structuralism 319
Figure 7.2 Development as a constructive web.
Domains
Counselor Father
Mother
Development
rats, or monkeys. This variability can easily elude overly
simple theoretical models that ignore the dynamic com-
plexity and interrelationships of living systems.
Variation and Order in Development: The
Constructive Web
People unknowingly ground their concepts and activi-
ties in metaphoric frames that give meaning (Lakoff &
Johnson, 1999). Concepts and theories in science derive
from metaphoric frames in the same way as everyday
concepts, except that research systematically tests their
grounding in observation and action. Traditional static
conceptions of development in psychological structure
are closely related to the widespread cultural metaphor
of a ladder. Development is conceived as a simple linear
process of moving from one formal structure to the
next, like climbing the fixed steps of a ladder. It matters
little whether the steps of the ladder are conceived as
cross-domain stages, levels of a domain-specific com-
petence, or points on a psychometrically based scale. In
each case, the beginning point, sequence of steps, and
endpoint of the developmental process are all linear and
relatively fixed, forming a single ladder. With such a
deterministic, reductionist metaphor, it is difficult to
represent the role of constructive activity or contextual
support because there appears to be no choice of where
to go from each step. The richness of children’s devel-
opment, including the variability in their skills across
contexts, is simply lost with the ladder metaphor. Devel-
opment means just moving to the next step—an overly
simple theory that clearly does not capture the variabil-
ity that Susan showed in her stories about nice and
mean interactions.
A more dynamic metaphor for development, which
includes variability as well as stability in development,
is the constructive web (Bidell & Fischer, 1992; Fischer
et al., 2003). The metaphor of a web is useful for dy-
namic models because it supports thinking about active
skill construction in a variety of contexts and for di-
verse variations. Unlike the steps in a ladder, the strands
in a web are not fixed in a determined order but are the
joint product of the web builder’s constructive activity
and the supportive context in which it is built (like
branches, leaves, or the corner of a wall, for a spider
web). The activity of an agent in constructing a web is
particularly clear. For example, a given strand may be
tenuous at first, dependent on surrounding strands for
external support, and like the spider, the person can re-
construct it until it becomes a stable part of the web.
Also, unlike most spider webs, human developmental
webs are constructed jointly by multiple agents, not by
an individual alone, although most psychological re-
search examines individuals isolated from their social
networks. We show how people often join together to
construct parts of their developmental webs.
The separate strands in a web represent the various
pathways along which a person develops. The strands in
a web can start in a number of places, take a variety of
directions, and come out at a range of endpoints, all de-
termined by active construction in specific contexts.
The several strands composing one line may be con-
structed in a different sequential order from the strands
composing another line in a different section of the web.
At the same time, there is order in the web, including
similar orderings of spatial positions for some strands,
separations and junctions of strands, and related starting
and ending points for some strands. Using the construc-
tive web as a metaphor for devising models of develop-
ment facilitates the unpacking of variability relating to
constructive activity and context, which are conflated in
the image of a linear ladder of static structures.
Figure 7.2 depicts an idealized constructive web. The
lines or strands represent potential skill domains. The
connections between strands represent possible rela-
tions among skill domains, and the differing directions
of the strands indicate possible variations in develop-
mental pathways and outcomes as skills are constructed

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320 Dynamic Development of Action and Thought
for participation in diverse contexts. Groupings of
strands represent domains of skill, such as mother, fa-
ther, and counselor, for each of the three clusters of
strands. Within each strand, people’s activities also
vary, demonstrating a developmental range (like
Susan’s) varying between high competence with contex-
tual support and lower competence without it (Fischer,
Bullock, et al., 1993; Fischer et al., 2003). In the discus-
sion that follows, the web metaphor is articulated to fa-
cilitate analysis of variability in the development of
dynamic skills.
DYNAMIC STRUCTURE IN COGNITIVE
AND EMOTIONAL DEVELOPMENT
To explain both variability and stability in development
and learning, an alternative framework is needed to re-
place the structure-as-form paradigm as a basis for re-
search and interpretation. Static conceptions of
psychological structure must be replaced with dynamic
ones such as the constructive web. Reified notions of
structures existing separately from human activity must
give way to a new understanding of structure as the dy-
namic organization inherent in the activity itself. Such a
framework is emerging in dynamic systems theory,
which is influencing a variety of fields and a growing
number of researchers. (This volume shows the extent of
the growth of dynamic systems in human development,
with a majority of chapters taking a dynamic systems
perspective.)
Common in many dynamic systems models is a shift
in the treatment of order and variation from being di-
chotomized to being intrinsically related (Hua & Smith,
2004; Kelso, 1995; Port & van Gelder, 1995; van Geert,
1998). Phenomena that were once viewed as random or
chaotic are now seen as organized in complex ways that
lead to specific patterns of variation. Descriptions and
models of the activity and change start with analysis of
relations between organization and variability in spe-
cific phenomena. For instance, the jagged patterns of
seacoasts—seemingly erratic jumbles of random ero-
sions—can be closely modeled with fractal geometry,
revealing an intrinsic organization to a geologic process
of erosion and sedimentation once thought of as disor-
derly. By recognizing that organization is related to
variability, geologists and mathematicians have been
able to create models of the dynamic organization of the
erosion process that can predict and explain the variabil-
ity observed in the changing coastline (Kruhl, Blenkin-
sop, & Kupkova, 2000). Similarly, biologists model the
structures of evolution of living organisms (Kauffman,
1993) and the dynamics of brain functioning and devel-
opment (e.g., Marcus, 2004; Polsky, Mel, & Schiller,
2004; Spruston & Kath, 2004).
Full realization of the potential of dynamic systems
analysis requires not only connecting nonlinear dynamic
concepts to psychological processes but also building
explicit dynamic models of those processes. Global con-
cepts can be powerful and useful, but ultimately they
must be tested out as models with explicitly defined
properties. Only with such models can researchers de-
termine whether the processes they hypothesize in fact
produce the dynamic patterns of development and varia-
tion that they expect (Fischer & Kennedy, 1997; Thelen
& Smith, Chapter 6, this Handbook, this volume; van der
Maas, 1995; van Geert, 1998; van Geert & van Dijk,
2002). Happily, computer-based tools including spread-
sheets such as Excel can be readily used to build explicit
dynamic models and test them against empirical data.
From a dynamic systems viewpoint, psychological
structure is the actual organization of systems of activ-
ity. It is not a separately existing entity, such as a logical
stage dictating behavior, or a preformed linguistic or
cognitive capacity awaiting actualization, but instead is
a property of human activity systems. Because real sys-
tems of activity are dynamic—constantly moving,
adapting, and reorganizing—they must be dynamically
structured. Variability is a natural consequence of sys-
tem dynamics, and because systems are organized, the
variability is not random but patterned, as evident in the
variable stories that Susan told. Just as geologists have
modeled the structures of coastal evolution and biolo-
gists have modeled the structures of evolution of living
species, developmental scientists can build models of
the dynamic structures of development and learning in
human action and thought.
To move beyond a general call to dynamic structural
analysis and model the dynamics of development
successfully, scholars need specific psychological con-
structs that support analyzing structures behind varia-
tion for particular research problems. There is not one
correct construct for a dynamic approach to psychologi-
cal structure. A number of contemporary constructs are
useful for this purpose because they have been devel-
oped specifically to facilitate analysis of variation and
organization of activities in context. The concept of
script, for example, focuses on the organization and
variation in everyday activities for storytelling, narra-
tives, goals, and recall for scripted activities in specific
contexts (Fischer, Shaver, & Carnochan, 1990; Nelson,

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Dynamic Structure in Cognitive and Emotional Development 321
1986; Schank & Abelson, 1977). The concept of strat-
egy has a long history of illuminating variations in the
organization of problem-solving activity (Bruner,
Goodnow, & Austin, 1956; Siegler & Jenkins, 1989;
Siegler, Chapter 11, this Handbook, Volume 2). Con-
cepts such as apprenticeship (Rogoff, 1990), environ-
mental niche (Gauvain, 1995), and setting (Whiting &
Edwards, 1988) facilitate analysis of the dynamic social
organization of activities across contexts.
A construct that we find especially useful for facili-
tating a dynamic approach to psychological structure is
dynamic skill; it provides a useful way of integrating
many of the necessary characteristics of dynamic psy-
chological structure into a single, familiar idea (Fischer,
1980b; Fischer & Ayoub, 1994; Fischer, Bullock, et al.,
1993). This construct is based on concepts that were
central to the cognitive revolution of the late 1950s and
1960s (Bruner, 1973; Gardner, 1985), the ecological
revolution of the 1960s and 1970s (Bronfenbrenner &
Morris, Chapter 14, this Handbook, this volume; Gibson,
1979), and the emotive revolution of the 1980s and
1990s (Campos, Barrett, Lamb, Goldsmith, & Stenberg,
1983; Frijda, 1986; Lazarus, 1991). These revolutions
have emphasized, for example, the importance of goals,
self-regulation, organism-environment interaction, bias
or constraint, and the social foundations of activity.
Most importantly, Piaget (1970) and Vygotsky (1978)
insisted on activity as the basis of cognitive structures,
defined as systems of relations among activities.
In the following discussion, we explicate the con-
struct of dynamic skill, using it to articulate essential
characteristics of psychological structures. We show
how the dynamic analysis of structure can both predict
and explain specific patterns of developmental variabil-
ity, focusing on three key types of variability frequently
observed in developmental research: (1) sequence, (2)
synchrony, and (3) range. In subsequent sections, we
show how these dynamic characteristics differ from
those in static views of structure, and we describe key
methodology for studying the dynamics of change, mi-
crodevelopment in learning and problem solving, devel-
opment of emotion, and the role of brain functioning in
development of cognition and emotion.
Psychological Structure as Dynamic Skill
In ordinary English usage, the term skill both de-
notes and connotes essential characteristics of the dy-
namic organization of human activities (Bruner, 1973;
Welford, 1968). Skill is the capacity to act in an organ-
ized way in a specific context. Skills are thus both
action-based and context-specific. People do not have
abstract, general skills, but they have skills for some
specific context: a skill for playing basketball, another
for telling a children’s story, or yet another for interper-
sonal negotiation. Skills do not spring up fully grown
from preformed rules or logical structures. They are
built up gradually through the practice of real activities
in real contexts, and they are gradually extended to
new contexts through this same constructive process
(Fischer & Farrar, 1987; Fischer & Immordino-Yang,
2002; Granott, Fischer, & Parziale, 2002).
The concept of skill also helps to conceptualize the
relations among various psychological, organismic, and
sociocultural processes and to cut through artificial di-
chotomies between mind and action, memory and plan-
ning, or person and context. A skill—such as telling
children stories about emotional interactions with other
children—draws on and unites systems for emotion,
memory, planning, communication, cultural scripts,
speech, gesture, and so forth. Each of these systems
must work in concert with the others for an individual to
tell an organized story to specific children in a particu-
lar context, in a way that it will be understood and ap-
preciated. The concept of dynamic skill facilitates the
study of relations among collaborating systems and the
patterns of variation they produce and inhibits treating
psychological processes as isolated modules that ob-
scure relations among cooperating systems. To see how,
let’s consider some of the characteristics of skills.
Integration and Interparticipation
Skills are not composed atomistically but are necessar-
ily integrated with other skills. The skill of playing bas-
ketball demands that many other skills, such as running,
jumping, and visual-motor coordination, all be inte-
grated to function in a coordinated way. Integrated
skills are not simply interdependent but interparticipa-
tory. True integration means that the systems participate
in one another’s functioning. Atomistic models allow
for simple interdependence: The stones in an arch, the
trusses in a bridge, the modules in a serial computer
comprise atomistic systems in which parts are interde-
pendent but do not obviously participate in each other’s
functioning.
In contrast, the components of living systems not
only depend on one another but participate in one an-
other. Although at first this concept may seem counter-
intuitive, there are many obvious examples in familiar
processes such as human cellular or organ systems. Any

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322 Dynamic Development of Action and Thought
system in the human body is composed of multiple sub-
systems whose boundaries defy definition. The cardio-
vascular system, for example, participates in the
functioning of every organ system, because every organ
depends on receiving oxygenated blood. At the same
time, the cardiovascular system includes components
from the nervous system, the muscular system, and so
forth, so that these other systems in turn participate in
the circulatory system. It makes little sense to think of
any of these systems as functioning outside the context
of the other systems: Living systems die when cut off
from the other systems with which they interparticipate.
For living systems, conceptions of structure must reflect
the interparticipation of one system in another.
Systems of activities are central parts of living sys-
tems, especially in complex systems such as human be-
ings. Activities organize into skills, which have many
interparticipating components. When Susan creates a
story of social reciprocity between the positive actions
of the doll Susan and her doll father, the actions of each
character affect each other intimately and recipro-
cally—they participate in each other. Skills normally
involve this interparticipation of components.
Context Specificity and Culture
Skills are context-specific and culturally defined. Real
mental and physical activities are organized to perform
specific functions in particular settings. The precise
way a given skill is organized—its structure—is essen-
tial to its proper functioning, as well as specific to that
skill at any moment. Good basketball players do not au-
tomatically make good baseball players; good story-
tellers in one culture do not automatically have their
stories understood and appreciated in other cultures.
The context specificity of skills is related to the char-
acteristics of integration and interparticipation because
people build skills to participate with other people
directly in specific contexts for particular sociocultural
systems. In turn, people internalize (Cole, 1996;
Wertsch, 1979) or appropriate (Rogoff, 2003) the skills
through the process of building them by participating in
these contexts; and as a result, the skills take on cultural
patterning. Similarly, component systems such as mem-
ory, perception, emotion, and even physiological regula-
tion all participate in the culturally patterned skills.
The context specificity of skills thus implies more than
simply a fit with an environment. Even systems like per-
ception or memory, which are often thought of as being
isolated from sociocultural systems, are linked to them
through the skills in which they participate; research
shows how pervasive and deep the connections are
(Greenwald et al., 2002; Mascolo, Fischer, & Li, 2003).
Self-Organization, Mutual Regulation, and Growth
Skills are self-organizing. Part of the natural function-
ing of skills is that they organize and reorganize them-
selves. These self-organizing properties go beyond
maintenance to include growth of new, more complex
skills. One of the goals of developmental science is to
analyze the processes of organization and change, which
skills undergo with development and learning. Unlike
mechanical systems that must be built and maintained
artificially through an external agency, the agency that
creates and maintains skills (and living systems in gen-
eral) resides in the activities for both individual activity
and social interaction. Construction and maintenance of
skills involves both self-regulation and mutual regula-
tion with other people, because components interpartic-
ipate. In an obvious example from human biology, as
people increase their activity level, their increased use
of energy and oxygen evokes increases in their rates of
breathing and metabolism. No outside agency is involved
in adjusting the controls for this interparticipation of
motor systems with respiratory and metabolic systems.
The living system actively adjusts itself to maintain its
own integrity.
In skills, the components regulate each other in the
same way. Susan’s and her father’s mean actions toward
each other mutually affected the other’s mean actions,
creating adaptations in content, organization, and emo-
tional tone (quality and intensity). Skills are not fixed
abilities but constantly adapting, regulated activity
structures. As Susan, her father, and her counselor act
together, they develop new skills together, coordinating
activities that were previously relatively independent to
form newly integrated wholes. Through coordination
and mutual regulation, they organize their activities into
qualitatively new, integrated systems, with sequences of
coordinations and regulations that build on each other.
Dynamic structuralism provides concepts and tools
for taking hold of this adaptive variability to uncover the
order behind the variations. One of the central discover-
ies is a common scale of hierarchical complexity that or-
ders the variations.
A Common Ruler for Skill Development
A key ingredient for advancing developmental science is
common rulers (scales) for measuring change and varia-

Page 12
Dynamic Structure in Cognitive and Emotional Development 323
Figure 7.3 Developmental cycles of levels and tiers of
skills. Development proceeds through 10 levels of skills
grouped into three tiers between 3 months and adulthood. The
ages of emergence are for optimal levels, the most complex
skill that a person can perform with social-contextual sup-
port, based on research with middle-class American or Euro-
pean children. They may well differ across social groups.
There is some evidence for an additional tier of innate action-
components in the first few months of life. Sources: From “A
Theory of Cognitive Development: The Control and Construc-
tion of Hierarchies of Skills,” by K. W. Fischer, 1980b, Psy-
chological Review, 87, pp. 477–531; and “The Big Picture for
Infant Development: Levels and Variations” (pp. 275–305), by
K. W. Fischer and A. E. Hogan, in Action in Social Context:
Perspectives on Early Development, J. J. Lockman & N. L.
Hazen (Eds.), 1989, New York: Plenum Press.
Abstractions
23–25 years
18–20 years
14–16 years
10–12 years
6–7 years
3�–4� years
2 years
11–13 months
7–8 months
3–4 months
Ab4. Principles
Rp3. Systems
Rp2. Mappings
Sm4/Rp1. Single Representations
Ab3. Systems
Ab2. Mappings
Rp4/Ab1. Single Abstractions
Sm3. Systems
Sm2. Mappings
Sm1. Single Actions
Tiers
Levels
Age of Emergence
Actions
Representations
tion in activity, similar to the Centigrade or Fahrenheit
scale for temperature and the meter or foot for length.
These scales should be grounded in properties of natural
response distributions and applicable across tasks and
domains. However, psychological measurement has pro-
duced mostly arbitrary scales based on one situation
such as those for intelligence, achievement, and person-
ality tests. They do not use naturally occurring response
distributions but statistical models assuming stable
(static) ability and normal distributions (van Geert &
van Dijk, 2002; Wahlsten, 1990), and they assess behav-
ior in one situation, the test. A more useful scale allows
measurement of different skills in various situations and
is not tied to one situation or assessment instrument.
Temperature and length can be measured in many ways
in virtually any situation.
Fortunately, the measurement problem has now
changed with the discovery of a common scale for be-
havioral complexity that captures a central dimension of
both long-term development and short-term change
(Commons, Trudeau, Stein, Richards, & Krause, 1998;
T. L. Dawson & Wilson, 2004; Fischer, 1980b; Fischer
& Immordino-Yang, 2002). Research with various meth-
ods has produced evidence for the same scale, marked
by clusters of discontinuities such as sudden changes in
growth patterns and gaps in Rasch scaling. Analysis of
growth curves has documented these patterns (Fischer
& Rose, 1999; van Geert, 1998), and Rasch (1980) scal-
ing of interview and test data has shown remarkably
consistent evidence of the same patterns of discontinuity
(Dawson, 2003; Dawson, Xie, & Wilson, 2003), forming
a scale of at least 10 levels of hierarchical complexity, as
shown in Figure 7.3. The scale relates to the outline of
developmental stages that Piaget (1983) described, but
the levels on the scale are better grounded empirically,
and performance varies across the scale instead of being
fixed at one point at each age. The scale also has impor-
tant similarities to those suggested by Case (1985),
Biggs and Collis (1982), and others. Interestingly, dis-
continuities in growth of brain activity seem to follow
the same scale, as described later in the chapter (Fischer
& Rose, 1996).
Many developmental scientists have posited stages,
some of which match some of the levels (Biggs & Collis,
1982; Case, 1985; Halford, 1982; McLaughlin, 1963),
but these alternatives have not been based on clear em-
pirical criteria for what constitutes a stage or level—and
what does not (Fischer & Silvern, 1985). Typically,
these investigators have merely described a sequence of
posited cognitive reorganizations without specifying
empirical criteria for stages or levels, except for loosely
defined “qualitative change” and an approximate devel-
opmental sequence.
The skill scale in Figure 7.3 begins with sensorimo-
tor actions, which are coordinated through several com-
plexity levels to eventually form representations, which
are in turn coordinated through several levels to form
abstractions, which continue to develop into adulthood.
The larger growth cycles of actions, representations, and
abstractions are called tiers (left column of the figure),
and the specific changes marked by clusters of disconti-
nuities are called levels (middle column). The ages in the
right column indicate when skills at a level first emerge
under conditions that support optimal performance.
Each level has a characteristic skill structure, as shown
in Figure 7.4, and similar structures recur in each tier,
reflecting a dynamic cyclical growth process. The struc-
tures begin with single sets organized as actions, repre-
sentations, or abstractions. A person coordinates and
differentiates these sets to form mappings, which in
turn are coordinated and differentiated to form systems.

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324 Dynamic Development of Action and Thought
Figure 7.4 Cycle of levels of development for a tier: cube
models and skill structures. The fourth level marks the cul-
minating structure for a tier and the formation of a new unit
for the next tier, as shown by the two skill formulas for Level
4/1: Level 4 actions form Level 1 representations, and Level 4
representations form Level 1 abstractions.
In skill formulas, brackets mark a skill structure; and
each letter denotes a skill component, with a large letter des-
ignating a main component (set) and a subscript or super-
script a subset of the main component. A line connecting sets
(—) = A mapping relation, a single-line arrow (↔) = A rela-
tion forming a system, a double-line vertical ( ) arrow = A
relation forming a system of systems, and a greater than sym-
bol (>) = A shift from one skill to another without integra-
tion. Such shifts between skills can occur at every level,
although for simplicity a shift is shown only at the first level.
For skill formulas in later figures and text, bold letters = Sen-
sorimotor actions, italic letters = Representations, and script
letters = Abstractions.
A
E
B
E
>
A
E
B
E
Level 2: Mappings
A
E
F
B
E
F
Level 4/1: Systems of Systems/Single Sets
B
E
F
A
E
F
C
G
H
D
G
H
T
X
Level 1: Single Sets
Level 3: Systems
Development
At the fourth level of each tier, the person coordinates
and differentiates systems to form systems of systems,
thus constructing a new unit that begins the next tier—a
single set of a new type. At the tenth level, the person
constructs single principles, and there is as yet no evi-
dence for further levels marked by clusters of disconti-
nuities beyond single principles (Fischer et al., 2003).
Contrary to static approaches to development and
learning, the levels on the scale do not indicate the use
of one psychological structure or module across do-
mains, like one of Piaget’s (1985) generalized logical
structures or Chomsky and Fodor’s (1983) modules.
People do not use the same structure across situations,
but they build skills along the same scale. The processes
of growth and variation produce skills that fit a common
scale across tasks and domains, but the skills used dif-
fer, being dynamically adapted to context, emotional
state, and goal. The complexity of separate activities
varies in similar ways for different contexts and states.
Think of temperature, for which physicists discovered a
common scale over the last several hundred years. The
same scale can be used to measure the temperature in
the sun, Antarctica, a refrigerator or furnace in New
York, a person’s mouth, or the bottom of the ocean.
Thermometers measure with a common scale across rad-
ically different situations and methods, even with great
differences in the ways that heat and cold occur.
In this way, skills are organized in multilevel hierar-
chies that follow the scale in Figures 7.3 and 7.4. People
construct skills through a process of coordination, as
when 5-year-old Susan built stories about emotionally
loaded social interactions that coordinated multiple ac-
tions into social categories and then coordinated social
categories into reciprocal activities. Susan used a skill
hierarchy in which individual pretend actions (Sm3 sys-
tems of actions) were embedded in social categories
(Rp1 single representations), which were in turn embed-
ded in socially reciprocal activities (Rp2 representa-
tional mappings). Existing component skills, controlling
activities in specific contexts, were intercoordinated to
create new skills that controlled a more differentiated
and integrated range of activities. In the newly inte-
grated skills, the component skills still functioned as
subsystems in the new skill as a whole. They also could
still be used alone, as when Susan dropped back to sim-
pler actions with less contextual support or with emo-
tional upset. We use representations of positive and
negative social interactions to ground the explanation of
dynamic skills and to illustrate how the skills in the di-
agrams both develop in the long term (macrodevelop-
ment or ontogenesis) and vary from moment to moment
(microdevelopment).
The skill hierarchy in the scale embodies the principles
of self-organization and interparticipation of dynamic

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Dynamic Structure in Cognitive and Emotional Development 325
systems. As skills become integrated and differentiated
at later levels, the component skills subordinate them-
selves to new forms of organization and mutual regula-
tion. The very process of creating new skills through
self-organizing coordination leads to a multileveled hier-
archical structuring of living skills. Indeed, “hierarchy”
in this sense has a special meaning. Computer programs,
for example, can be arranged hierarchically in the sense
that lower-level outputs feed higher-level procedures, but
this organization does not typically involve interpartici-
pation and self-organization.
Generalization through Construction
Susan built her skills for representing positive and
negative social interactions in one context, but she nat-
urally tried to generalize those skills across related
contexts—for example, using the skills for represent-
ing interactions with her father to build representa-
tions of interactions with her counselor. The process of
skill construction through coordination is closely re-
lated to skill generalization, and the complexity scale
can illuminate both. Generalization of mental and
physical activity involves specific building of general-
ized skills driven by the goal-oriented activity of an
individual or ensemble (a few people working closely
together), especially for socially constructed domains
such as literacy, mathematics, and science. General-
ization in these domains is not a predetermined, innate
outcome waiting for development to catch up with it,
as some nativists would have it (Baillargeon, 1987;
Fodor, 1983; Spelke, 1988). Several mechanisms of
generalization of dynamic skills through coordination,
differentiation, and bridging from simple to complex
have been specified with some precision (Fischer &
Farrar, 1987; Fischer & Immordino-Yang, 2002;
Siegler & Jenkins, 1989). Studying microdevelopment
is an especially powerful way of analyzing processes
of dynamic generalization, as we describe in a later
section to illuminate how learning general knowledge
takes a long time.
Building a Constructive Web for Positive and
Negative Social Interactions
The complexity scale combines with the constructive
web in Figure 7.2 to support analyzing psychological
structure in dynamic terms. Unlike the traditional
ladder of development, the web highlights integration,
specificity, multiple pathways, active construction, and
other central properties of skill development (Bidell &
Fischer, 1992; Fischer et al., 2003). Building a web is a
self-organizing process in which a person coordinates
and differentiates various activities along the complex-
ity scale. The strands in a web are the joint product of
the person’s constructive activity and the contexts in
which skills are built, including the other people who
coparticipate in building them.
We use stories about nice and mean social interac-
tions to illustrate properties of the constructive web
and its relation to dynamic properties of cognitive and
emotional development. Telling a story or narrative is a
fundamental human activity. To produce a specific
story or narrative, a child needs to organize activities
in a scriptlike way, following specific patterns of se-
quencing of events (Bruner, 1990; Fischer et al., 1990;
Ninio & Snow, 1996; Schank & Abelson, 1977). This
organization helps impart meaning to the narrative, as
with 5-year-old Susan’s stories about interaction be-
tween a girl and her father. Without this script organi-
zation, the story becomes a meaningless jumble; for
example, it becomes unclear who is being nice to whom
and why, or who is hurting whom and why. Yet the or-
ganization of the storytelling activity must also be
flexible, so that a storyteller can create new versions
for changing situations and people, thereby communi-
cating different ideas and feelings, as Susan changed
her stories in relation to her emotional state and to the
contextual cuing and support she received from the
adult interviewer.
Like other skills, the complexity and organization of
story skills varies widely with the dynamics of the con-
structive activity, including story complexity, emotional
state, and social-contextual support from other people.
The skill scale illuminates this variation by providing
a ruler for analyzing and comparing these variations.
When 5-year-old Susan is in a positive mood and has
support from her counselor, she organizes a complex
story about positive interactions. A few minutes later
when she is emotionally stressed, she no longer pro-
duces a complex positive story, even with support from
the counselor, but instead tells an equally complex nega-
tive story. When the counselor does not provide contex-
tual support, Susan can organize only a simpler positive
or negative story. In addition, the form of narrative
organization varies across cultural groupings and
discourse communities because individuals construct
different narrative skills to participate in different
culturally patterned communicative activity. Susan’s

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326 Dynamic Development of Action and Thought
Figure 7.5 Developmental web for nice and mean social interactions. The numbers to the left of each set of brackets indicate
the step in complexity ordering of the skill structures. The words inside each set of brackets indicate a skill structure. The left
column designates the first step at each skill level.
NICE
MEAN
NICE and MEAN
Rp1
Level
Rp2
Rp3
1
ME
NICE
1
YOU
MEAN
>
2
YOU
MEAN
ME
NICE
3
YOU
NICE
ME
NICE
3
MEAN
ME
ME
NICE
3
YOU
MEAN
MEAN
ME
>
4
YOU
MEAN
MEAN
ME
YOU
NICE
ME
NICE
5
YOU 1
MEAN
YOU 2
MEAN
MEAN
ME
5
ME
NICE
YOU 1
NICE
YOU 2
NICE
6
YOU 1
NICE
YOU 2
MEAN
MEAN
NICE
ME
7 YOU
NICE 2
NICE 1
ME
NICE 2
NICE 1
7 YOU
MEAN
NICE
ME
MEAN
NICE
7 YOU
MEAN 2
MEAN 1
ME
MEAN 2
MEAN 1
stories fit her cultural community, but would have to be
reorganized to fit others.
Webs and Biases
Figure 7.5 shows a developmental web for stories about
positive and negative social interactions in American
children of diverse ethnicity and social class (Ayoub &
Fischer, in press; Fischer & Ayoub, 1994). When chil-
dren play, they commonly act both nice and mean to
each other, and like 5-year-old Susan, they readily act
out and tell stories about positive and negative interac-
tions between peers. The web has three distinct strands

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Dynamic Structure in Cognitive and Emotional Development 327
organized by emotional domains of different valence—
nice on the left, mean on the right, and the combination
of nice and mean in the middle. The tasks are ordered in
steps by skill complexity, marked by the numbers next to
each skill structure. There are normally multiple steps
per level, marking the distinct points in the construction
process that can be discriminated for a particular situa-
tion, which can vary in number. The levels are indicated
in the left-hand column.
In the research, children between 2 and 9 years of age
told stories about two or three boys or girls playing to-
gether, with each story reflecting one of the three emo-
tional domains. One character usually had the name of
the child telling the story, and the others represented his
or her friends or siblings; in some studies, the characters
had the names of unknown children. In a separate as-
sessment, children also told similar stories about parent-
child interactions.
Later steps generally involve more inclusive skills,
constructed by the coordination and differentiation of
lower-level components. For example, in step 3, the
story involves a mapping between two instances of nice-
ness (or meanness), similar to the reciprocity stories of
Susan: One doll acted mean (or nice) to a second doll
who because of the first doll’s action, acted mean (or
nice) in return. In Figure 7.5, each diagram of YOU or
ME acting NICE or MEAN represents a story with a cer-
tain skill structure, varying across the three skill levels
of single representations, mappings, and systems. The
structure
represents a mapping for reciprocity: If you are nice
to me, I will be nice to you. Vertical arrows be-
tween specific story structures in Figure 7.5 indicate
developmental sequencing for those stories, as when
steps 3, 4, and 5 in the left column form part of a path-
way along the strand for nice. The skill formulas focus
on the central elements that children had to control in
the nice/mean stories: roles (you or me), emotional va-
lence (nice or mean), and relations between roles
(shifts without coordination, mappings, and systems).
Like structures in any living system, these elements
subsume many additional components hierarchically
within them such as actions, perceptions, feelings,
goals, and social expectations.
Thus, each step in Figure 7.5 represents a different
level of skill at conceptualizing relations among social
(1)
YOU
NICE
ME
NICE
interactions. Children’s stories develop along strands
for each of the content domains of nice, mean, and
nice-and-mean in combination. When stories are paral-
lel from left to right, they emerge at approximately the
same time in development. Their development also
shows many connections among the strands.
In accord with the general tendency for researchers
to neglect within-person variation and emphasize
between-person variation, people sometimes misunder-
stand this developmental web, interpreting it to mean
that different children are developing along each strand.
To the contrary, each child develops simultaneously
along each of the strands in the web in Figure 7.5. That
is, each child is simultaneously developing understand-
ings about positive valence (how nice interactions
occur), negative valence (how mean interactions occur),
and combined valence (how nice and mean can be com-
bined in an interaction). When the three strands are all
closely parallel, with no clear bias toward one or the
other, then the web looks like Figure 7.5, with complex-
ity as the primary determinant of developmental order-
ing. Steps of the same complexity are parallel in the
web, independent of valence.
One characteristic of emotions, however, is that peo-
ple typically show biases in their actions and thoughts.
Biases toward certain action tendencies are one of the
defining characteristics of emotions, as is discussed in
the later section on Emotional Development. Emotional
biases often have strong effects on a developmental web;
they shift relations between strands, and they change de-
velopmental orderings. For the nice-and-mean web, one
far-reaching emotional bias is a general favoring over
time of one pole of evaluation—toward positive (nice) or
negative (mean). One of the most strongly established
findings in social psychology is that most people show
positive biases in their activities and evaluations, espe-
cially for attributions about themselves (Higgins, 1996;
Osgood, Suci, & Tannenbaum, 1957). Figure 7.6 shows
a global bias toward the positive.
Although positive biases are pervasive, there
are also many instances of negative biases. Powerful
biases toward the negative can be produced by trauma
such as child abuse (Ayoub, Fischer, & O’Connor,
2003; Westen, 1994) and by implicit attitudes (Green-
wald et al., 2002). When children show a strong and
persistent bias toward the negative and against the pos-
itive, their entire developmental web is shifted (biased)
in the opposite direction than in Figure 7.6—toward
the negative pole. That is, mean interactions are under-
stood earlier than nice ones, and the combination of

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328 Dynamic Development of Action and Thought
Figure 7.6 Developmental web biased toward nice interactions. This web includes only the first two-thirds of the skills from
the web in Figure 7.5.
NICE
MEAN
NICE and MEAN
1
ME
NICE
3
YOU
NICE
ME
NICE
>
2
YOU
MEAN
ME
NICE
1
YOU
MEAN
5
ME
NICE
YOU 1
NICE
YOU 2
NICE
3
MEAN
ME
ME
NICE
>
4
YOU
MEAN
MEAN
ME
YOU
NICE
ME
NICE
3
YOU
MEAN
MEAN
ME
5
YOU 1
MEAN
YOU 2
MEAN
MEAN
ME
6
YOU 1
NICE
YOU 2
MEAN
MEAN
NICE
ME
nice and mean is delayed as well. A number of abused
children and adolescents show an alternative develop-
mental pathway based on this bias toward the negative
(Fischer et al., 1997; Rappolt-Schlichtman &
Ayoub, in press). Besides the long-term effects of expe-
rience, there are short-term within-person effects as a
function of context, mood, and similar factors, as when
being in a negative mood leads to a bias toward negative
stories. In this way, developmental webs can be use-
ful for representing variations in developmental path-
ways not only between people but also within a person
over time.
Modeling Nonlinear Dynamic Growth in a Web
Besides the representations of weblike relations between
steps and strands like those in Figures 7.2 and 7.5,
various tools can be useful for analyzing different prop-
erties of development. One example that can be particu-
larly powerful is mathematical modeling of growth
functions (Singer & Willett, 2003). Each strand in a web

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Dynamic Structure in Cognitive and Emotional Development 329
Figure 7.7 Growth functions showing a bias toward nice in-
teractions. Skill Step refers to the complexity ordering in
Figure 7.5. Level refers to the level of hierarchical complex-
ity in Figure 7.3.
0
1
2
3
4
5
Age in Years
2
1.5
0
2.5
3
3.5
4
Skill Step and Lev
el
Rp1
Rp2
Nice
Nice and Mean
Mean
can be described in terms of its growth function, which
in this case is represented by a nonlinear dynamic
growth model (Fischer & Kennedy, 1997; van Geert,
1991, 2003). Figure 7.7 shows an example of growth
curves produced by the model for each of the three
strands.
The growth model includes a global positive bias like
that in Figure 7.6, and under certain conditions, it also
produces stagelike jumps in development, which are dis-
cussed in the next section. Complexity scaling provides
the metric for quantifying growth of the strands, with
scaling tools provided by dynamic skill theory. The
graph clearly represents the bias toward positive valence
and away from negative and combined valences, empha-
sizing the quantitative advantage of the nice strand over
the others. The graph also highlights the fits and starts
in growth and the relations between them—something
that is not evident in the web diagram. However, this
quantitative graphing de-emphasizes the ordering rela-
tions among specific story structures, which are clearly
marked in Figures 7.5 and 7.6. Different tools for analy-
sis of developing activity structures capture different
properties of the structures, and no single tool captures
all important aspects.
How Dynamic Skills Explain Variability
in Development
The characteristics of skills, including the weblike pro-
cess of skill construction, can help both explain and
predict patterns of variability that have eluded tradi-
tional static accounts of psychological structure. In this
section, we show how three basic forms of systematic
developmental variability—(1) complexity level, (2) se-
quence, and (3) synchrony—can each be explained by
the characteristics of dynamic skills. In a subsequent
section, we consider issues of methodology and mea-
surement used in the precise description and prediction
of variability in development.
Developmental Range: Optimal and Functional Levels
Children (and adults) routinely perform across a range
of skill levels, like Susan telling stories about nice and
mean at two different levels with her counselor. A fun-
damental error stemming from static conceptions of
psychological structure is that each individual is treated
as “possessing” one fixed level of structure, either
across domains or in a domain, as if cognition were a
sealed bottle with a fixed level of liquid in it. From this
point of view, an individual’s behavior is expected to be
homogeneously consistent with the fixed level of cogni-
tion such as the number of items that a child can sustain
simultaneously in working memory. Deviations from
this fixed level then seem mysterious and appear to call
for complicated explanations. Often the deviations are
ignored, as researchers mistakenly use methods that
sum across individuals, activities, and contexts and treat
true variations in level as errors of measurement (Estes,
1956; Fischer, Knight, & Van Parys, 1993; Skinner,
1938; van Geert & van Dijk, 2002).
A person possesses different competences in differ-
ent contexts and emotional states. The types and com-
plexities of organization found in dynamic skills are
always changing because (a) people constantly vary
their activities as they adjust to varying conditions and
coparticipants, and (b) people commonly reorganize
their skills to deal with new situations, people, and
problems. For instance, a tennis player plays at top level
one day—after a good night’s rest, on an asphalt court,
against a well-known opponent. The same player plays at
a much lower level the next day, with a bad night’s sleep,
on a clay court, against a new adversary. This reduction
in the player’s skill level is a real change in the organi-
zation of activity, not a departure from some underlying
stage or competence that is the “real” thing. The person
unconsciously changes the actual relationships among
the participating systems of perception, motor anticipa-
tion, motor execution, memory (for instance, of the
other player’s strengths), and so on. These relations

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330 Dynamic Development of Action and Thought
constitute the dynamic structure of skill. The level of
organization of tennis skills varies because coordina-
tion among the systems is different on the 2 days. To
posit any additional layers of abstract competence or
stage structure to explain this variation is unnecessary,
as it is accounted for by the dynamic properties of real
activity systems.
Comparable variations in skill level occur in most
skills, from playing tennis to interacting socially, plan-
ning a party, and reasoning about scientific or literary
questions. Vygotsky (1978) spoke of the zone of proxi-
mal development (ZPD) and the variation between
performances as a result of presence and absence of
scaffolding by an expert. Our research has documented
an important principle of variation in this zone: the de-
velopmental range introduced earlier, which is the inter-
val between a person’s best performances with and
without social contextual support in some domain.
Susan showed a developmental range in her construction
of stories about nice and mean interactions.
In a study of nice and mean stories, 7-year-old chil-
dren telling stories under conditions of high and low
social-contextual support showed a consistent develop-
mental range, repeatedly changing to a high level with
support and a lower level without it, as shown in Figure
7.1 and Table 7.1 (Fischer, Bullock, et al., 1993). A typ-
ical 7-year-old produced a highest story at step 3 (Level
R2, representational mappings) under low-support con-
ditions but achieved step 6 (Level Rp3, representational
systems) under high-support conditions. The interval
between these two developmental levels (a child’s devel-
opmental range for this domain) is indicated in Table
7.1, which is based on the data in Figure 7.1. The high-
est skill level when functioning independently (under
low support) for a given domain is referred to as the
functional level. The highest level with high-support
conditions is the optimal level.
The interval of variation for a given skill can extend
even farther, as suggested in Table 7.1. Social support
often goes beyond prompting or modeling to actual co-
participation in a task (also called scaffolding), where,
for example, an adult takes on acting out the role of one
of the dolls in a story with a child. With scaffolding, the
level of task performance can be extended several steps
upward because psychological control of the activity is
shared with an expert. In contrast, circumstances such
as emotional stress, fatigue, distraction, or interference
by a coparticipant can lead a person’s skill level to fall
below his or her functional level.
Developmental range seems to characterize perfor-
mance across most tasks, ages, and cultures, and it
grows larger with age, at least through the late twenties
(Fischer, Bullock, et al., 1993; Fischer et al., 2003).
Most people experience the developmental range di-
rectly when they learn something new with a teacher or
mentor. With the prompting of the teacher, they under-
stand a new concept or control a new skill at a relatively
high level. Without the prompting, their level of skill
drops precipitously such as when they leave the class-
room and try to explain the new concept to a friend who
knows nothing about it.
A study of Korean adolescents’ conceptions of
themselves in relationships illustrates the striking gap
that commonly occurs between optimal and functional
levels, as shown in Figure 7.8 (Fischer & Kennedy,
1997; see also Harter & Monsour, 1992; Kennedy,
1991). In this study, adolescents participated in the
Self-in-Relationships Interview (SiR), which assessed
developmental level under two conditions (described
in more detail in the section on Methodology of Dy-
TABLE 7.1 Developmental Range of a 7-Year-Old Telling a Story with
Varying Social Support
Step
Skill Level
Performance Level
Social Support
1
Rp1
2
3
Rp2
Functional level
None
4
5
6
Rp3
Optimal level
Priming through Modeling, etc.
7
8
Ab1
Scaffolded level
Direct participation by adult
9
Note: Functional and optimal levels are upper limits on performance, which show sta-
bility for a task. Scaffolded level involves a range of performance indicated by the
vertical line on the left, with the specific step depending on the nature of the scaf-
folding in combination with the 7-year-old’s skill.

Page 20
Dynamic Structure in Cognitive and Emotional Development 331
Figure 7.8 Range of developmental levels for Self-
in-Relationships Interview in Korean adolescents.
13
12
11
10
9
8
0
1
2
3
4
5
6
Mean Step and Lev
el
Grade
Abstract Systems
Abstract Mappings
Single Abstractions
Rp3
Ab1
Ab2
Ab3
Optimal Level
Functional Level
0
Figure 7.9 Developmental range of a web for two
relationships.
Mother Best Friend
Automatic
Functional Level
Optimal Level
Scaffolded Level
Degree of Support
Development
namic Structural Analysis). For the optimal-level
condition, high support involved the construction
by each adolescent of a detailed diagram of his or her
own descriptions of self in several different relation-
ships such as with mother, father, sibling, best friend,
and teacher. The diagram as well as the interview
questions supported optimal performance by prompt-
ing key components of skills. For the functional-level
condition, low support involved a relatively open-ended
interview that was similar to most traditional assess-
ments of self for adolescents; they were simply asked
to describe what they were like in each relationship and
how their descriptions related to each other. There was
no prompting of key skill components.
The constructive web provides another useful way of
portraying variability in developmental level. Figure
7.9 represents a developmental web for an individual’s
conceptions of self in two important relationships,
mother and best friend. Along each strand the heavy
solid line indicates a well established, highly automa-
tized skill for a given context. An individual’s perfor-
mance drops to this level in circumstances of high
stress, fatigue, or interference. The thinner solid strand
represents the functional level of independent control
under normal conditions for this context—a level of
skill organization that is well established but less auto-
matic. The optimal-level skills indicated by the dashed
lines are still under construction, occurring when the
person receives modest contextual support such as
modeling or prompting. Finally, the dotted lines indi-
cate a skill level that the individual has recently begun
to construct, in which the person can hold the compo-
nent skills in an integrated structure only if there is
direct scaffolding, coparticipation of a more capable
partner.
From this perspective, it is easy to see why skill
levels vary over a wide range. The variation is a direct
consequence of the active, constructive, and context-
embedded nature of human activity. As Figures 7.8 and
7.9 suggest, adolescents’ conceptions of themselves in
relationships are not fixed capacities but multilevel
structures of dynamic skills under construction. Skills
early in a particular developmental sequence are better
integrated and more stable across time and conditions
than skills more recently constructed or just starting to
be constructed. Variability in the organization of a per-
son’s skill at holding in mind and organizing the events
and characteristics of a social relationship are a natural
consequence of these constructive dynamics. There
is no need to invoke explanations in terms of formal
stage structures or hidden competences hovering over
and guiding activities. Variability is explained by con-
structive dynamics. The task is to build theoretical
models and methods for describing and analyzing these
dynamics.
The Dynamics of Stages and Developmental Synchrony
Besides explaining sources of variability in level, the
concept of dynamic skill also provides a framework for
facilitating analysis of processes of change in construc-
tive dynamics. Specifying the conditions that lead to

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332 Dynamic Development of Action and Thought
variability, as in developmental range, allows the control
and use of the conditions to analyze patterns of change.
We have employed this control of conditions to illumi-
nate a classic argument about processes of change, the
stage debate (Bidell & Fischer, 1992). Traditionally the
dialogue about stage has not always been informative,
amounting to assertion without accommodation:
Stage proponent: “There are stages of cognitive
development.”
Nonstage proponent: “No, there are no stages.”
Stage proponent: “Yes, there are.”
Nonstage proponent: “No, there aren’t.”
Instead of arguing about whether stages exist, dynamic
skill analysis provides tools for specifying the conditions
for stagelike change and those for continuous, nonstage-
like change. Stages both do and do not exist, depending
on the dynamics of the conditions of activity!
In the study of Korean adolescents, dynamic skill
theory was used to predict the conditions and age inter-
vals when growth shows discontinuous jumps in level
versus smooth change. High-support conditions were
predicted to produce two discontinuities marking the
emergence of two new levels of coordination of ab-
stractions. Figure 7.8 shows the predicted difference in
growth functions: Optimal-level growth spurted twice,
at grades 11 and 13, which are comparable to the
ages of optimal-level spurts found in research with
American and Chinese samples (Cheng, 1999; Fischer
& Kennedy, 1997; Harter & Monsour, 1992; Wang,
1997). Researchers using the skill theory framework
have observed similar patterns in other types of skills,
in age groups ranging from preschool to adulthood
(e.g., Corrigan, 1983; Fischer & Hogan, 1989;
Fischer et al., 2003; K. Kitchener, Lynch, Fischer, &
Wood, 1993). In each case, the developmental spurt is
associated with a major transition in skill level such as
the transitions to abstract mappings and abstract sys-
tems under optimal conditions in Figure 7.8. When op-
timal and functional levels are lumped together, this
discontinuity is masked because the developmental
function produced is effectively an average of two dif-
ferent developmental functions, a process that in-
evitably masks the true growth functions. In addition,
there is much evidence of other kinds of discontinuities
such as gaps in Rasch scaling and changes in brain-
wave patterns at similar points along the hierarchical
complexity scale (Dawson, 2003; Dawson et al., 2003;
Fischer & Rose, 1996).
As this and many other examples demonstrate, the
developmental level of behavior varies with assessment
context, coparticipant, state of arousal, emotional state,
and goal, just to name a few of the most obvious sources
of variation. Some researchers have argued that these
variations demonstrate an absence of developmental
stages (Brainerd, 1978; Flavell, 1982; Thelen & Smith,
1994), but these arguments overlook the order in the
variability. The organization of behavior develops sys-
tematically, and it also varies from moment to moment.
These facts are contradictory only for overly simple
concepts of stage and variation. Real behaviors—and
real neural networks as well—function not at a single
level but in a range or zone (A. Brown & Reeve, 1987;
Fischer, Bullock, et al., 1993; Grossberg, 1987; Vygot-
sky, 1978). Research to test for stagelike change must
take this range into account and analyze which parts of
the variation show stagelike characteristics and which
do not. Only then will the field move beyond endless ar-
guments in which protagonists focus on only part of the
variation and thus draw half-baked conclusions.
The separation of optimal and functional is one ex-
ample of the way a dynamic skills framework permits
the prediction and explanation of patterns of variability
that have typically been ignored or explained away by
theories relying on static stage or competence models
of psychological structure. Although researchers may
differ with the specific interpretation given to a phe-
nomenon like the discontinuities in optimal level, the
constructive-dynamic framework described here makes
it possible to debate the issues empirically, by providing
concepts and research methodologies to control and ma-
nipulate variations in the developmental process. (These
methodologies are described throughout this chapter;
see also the section on Methodology.)
An important part of “stage” is the expectation of
high developmental synchrony. Stage theories predict
high stability across contexts in the level of performance
an individual will display. The idea of a “hard stage,” an
underlying logical system pervading the mind at a given
stage (Kohlberg, 1984; Piaget, 1985), implies that a given
person should perform logically equivalent tasks at the
same time regardless of state or context—say, Piaget’s
tasks of conservation of liquid and classification of
shapes in matrices. It is as if Piaget touched children’s
heads on their seventh birthday, and instantly they were
transformed into concrete operational thinkers. This
strong “point synchrony” (simultaneous development of
new levels across domains) is seldom empirically sup-
ported (Fischer & Bullock, 1981). Instead, children and

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Dynamic Structure in Cognitive and Emotional Development 333
adults show a high degree of variability in levels across
tasks and contexts, even with tasks that are logically sim-
ilar. For example, children who understand tasks for
conservation of number frequently fail tasks for conser-
vation of liquid even when the procedures and questions
are similar.
On the other hand, there is evidence of real develop-
mental synchrony as well when dynamic concepts are
used to analyze how and when synchrony does and does
not occur. Equivalent concepts show what is sometimes
called “interval synchrony,” appearing not at the same
time but within a relatively short time interval of each
other. Moreover, this interval is much smaller for con-
cepts about closely related topics measured in similar
tasks, especially when there is a clearly defined concep-
tual structure that is ecologically valid (T. L. Dawson &
Gabrielian, 2003; K. Kitchener & King, 1990; Pirttil�-
Backman, 1993). The disparity in intervals between
concepts drops as differences in content, context, and
concept are reduced. Case and his colleagues (1996)
have even shown that, with a well-defined central con-
ceptual structure, teaching the structure increases the
degree of synchrony across domains to the point that it
sometimes accounts for approximately 50% of the vari-
ability—a remarkably large effect indicating high inter-
val synchrony. Lamborn, Fischer, and Pipp (1994)
demonstrated that development of understanding of spe-
cific moral concepts such as honesty and kindness re-
lated closely to relevant social problem-solving skills
but not to other problem-solving skills.
The combination of systematic variability and syn-
chrony is hard to explain with static concepts of psycho-
logical structure such as stage or competence. Piaget
and other hard-stage theorists initially waved away evi-
dence by arguing that different tasks posed different
forms of resistance to structures of logic. The resulting
decalages (time gaps) were said to result from different
kinds of resistance, but the processes by which resist-
ance functioned were never explained (Kohlberg, 1969;
Piaget, 1971).
The principles of constructive dynamics explain pat-
terns of variation in stage patterns and synchrony in a
straightforward manner:
• Skills are constructed hierarchically by integrating
earlier skills into a more inclusive whole.
• Skills vary across multiple levels for each individual
depending on context, goal, state, support, and
other factors. An important example is the develop-
mental range.
• Skills are constructed for participation in specific
tasks and contexts and over time can be generalized
to others through specific generalizing activity
(Case et al., 1996; Fischer & Farrar, 1987; Fischer &
Immordino-Yang, 2002).
Even in the simple diagram of two domains in Figure
7.9, it is obvious that among the functional, optimal, and
scaffolded levels, some skills will be the same across do-
mains, and others will be different for the same domain.
Taken together, these principles help explain how inter-
val synchrony occurs as well as how people build gen-
eral skills. This process is elaborated later in the section
titled: Building Structures: Transition Mechanisms and
Microdevelopment.
The scale for hierarchical complexity in Figures 7.3
and 7.4 provides a metric for assessing greater or lesser
synchrony, moving beyond all or none arguments. For
many related skills, levels do not show complete asyn-
chrony but are relatively close even when they differ.
The growth functions for nice and mean in Figure 7.7 il-
lustrate how the same growth curves can simultaneously
show similarities and differences in the ages of change.
Stepping back to look at the broad sweep of change
makes the synchronies evident; stepping close to look at
the details of change highlights the disparities. Each
new skill at a higher level is built from similar lower-
level skills: Each extension of a skill to a new level is a
constructive generalization constrained by the compo-
nent skills available. There is no need to invoke perva-
sive logical structures or innately determined formal
constraints to account for interval synchrony in develop-
ment. The dynamics of the construction of skills in con-
text explain both the variability and the synchrony found
in patterns of variation.
Variability in Sequence of Acquisitions
Another form of variation involves the sequence in
which skills for a given task or context are constructed,
often called developmental sequences or pathways. Al-
though evidence of variation in specific developmental
sequences has been taken as evidence against hierarchi-
cally constructed stages (Brainerd, 1978; Gelman &
Baillargeon, 1983), a dynamic structural analysis illu-
minates when sequences occur and when they do not,
whereas stage and competence theories are hard pressed
to account for observed patterns of variability and sta-
bility in sequences.
An examination of the evidence shows a familiar
pattern: There is high variability in developmental

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334 Dynamic Development of Action and Thought
sequences, but this variability is neither random nor ab-
solute. The number and order of steps in developmental
sequences vary as a function of factors like learning
history, cultural background, content domain, context,
coparticipants, and emotional state. In addition, the vari-
ability in steps appears to be contingent on the level of
analysis at which the sequence is examined (Dawson &
Gabrielian, 2003; Fischer, 1980b; Fischer et al., 2003).
Developmental sequences tend to appear mainly at
two levels of analysis: (1) large-scale, broad sequences
covering long times between steps, relatively indepen-
dent of domain, and (2) small-scale, detailed sequences
found within particular domains. Large-scale sequences
appear to be relatively invariant. Children do not, for in-
stance, exhibit concrete operational performances
across a wide range of tasks, and then years later begin
to exhibit preoperational performance on related tasks.
On the other hand, small-scale sequences have often
been found to vary dramatically (Ayoub & Fischer, in
press; Wohlwill & Lowe, 1962).
Typically, variation in small-scale sequences is asso-
ciated with variation in task, context, emotion, copar-
ticipant, or assessment condition. For instance, Kofsky
(1966) constructed an eleven-step developmental se-
quence for classification of objects based on Inhelder
and Piaget’s (1964) concrete-operational thinking and
used scalogram analysis to rigorously test the sequence.
Her predicted sequence followed a logical progression,
but it drew on an assortment of different tasks and mate-
rials to evaluate each step. The results showed weak
scalability with several mini-sequences.
Other sources of variation in small-scale sequences
include cultural background, learning history, learning
style, and emotion. Price-Williams, Gordon, and
Ramirez (1969), for instance, examined the order of ac-
quisition of conservation of number and substance in
two Mexican villages. The villages were comparable in
most ways except that in one village the children partic-
ipated in pottery making from an early age. Children of
the pottery-making families tended to acquire conserva-
tion of substance (tested with clay) before conservation
of number, while nonpottery-making children showed
the opposite tendency.
Affective state can also powerfully affect develop-
mental sequences (Ayoub & Fischer, in press; Fischer &
Ayoub, 1994). For example, inhibited and outgoing chil-
dren show different sequences in representing positive
and negative social interactions, especially those involv-
ing the self. Inhibited children often show the positive
bias in Figure 7.6. Extreme emotional experiences such
as child abuse often lead to highly distinctive develop-
mental sequences for representing self and others in re-
lationships, as we discuss in the section on Emotions.
Furthermore, the failure to consider variation in se-
quences from factors such as learning style, disability,
or cultural difference leads to combining undetected
variations, with the result that task sequences erro-
neously seem to scale poorly (Fischer, Knight, et al.,
1993). As soon as they are resolved into alternative se-
quences, they scale well. For example, a sequence of six
tasks related to reading single words scaled weakly
when tested on a sample of poor readers in first to third
grades (Knight & Fischer, 1992). In each task, a child
dealt with an individual word, reading it directly (Read-
ing Production), reading it through matching it with a
picture (Reading Recognition), producing a word that
rhymes with it (Rhyme Production), recognizing a word
that rhymes with it (Rhyme Recognition), naming the
letters seen in the word (Letter Identification), or de-
scribing what the word means (Word Definition). Use of
a scaling technique for detecting alternative sequences
showed the existence of three different well-ordered se-
quences in the sample. Subsamples of poor readers
showed sequences that reflected their specific reading
difficulties.
The constructive web framework provides a tool for
rethinking these patterns of variation in the construc-
tive dynamics of skill development. Alternative develop-
mental pathways can often be traced for different groups
of children such as the three pathways for good and poor
readers. When the standard metaphor of the develop-
mental ladder is used, children are compared only in rel-
ative progress or delay on a single progression from low
to high performance on a single sequence. As long as
only a single pathway is considered, there seems only
one remedial choice: to work to speed up the apparently
delayed group along the “normal” pathway.
Figure 7.10 shows the three weblike pathways that
the students take through the series of reading tasks. For
each group, the order of acquisition for the six tasks was
tested using partially ordering scaling, a statistical tech-
nique that is based on the logic of Guttman scaling
(Krus, 1977; Tatsuoka, 1986). A line between two tasks
means that the ordering is statistically reliable. A com-
parison of the three developmental pathways shows that
the poor readers are not delayed with respect to a univer-
sal sequence, but actually follow different pathways of
acquiring these skills. Normal readers all showed one

Page 24
Dynamic Structure in Cognitive and Emotional Development 335
Figure 7.10 Developmental pathways of good and poor readers. The normative pathway for most good readers is shown in (a:
Pathway 1: Normative developmental pathway for reading single words), whereas the two less integrated pathways followed by
poor readers are shown in (b: Pathway 2: Independence of reading and rhyming), and (c: Pathway 3: Independence of reading,
letter identification, and rhyming). From “Growth Cycles of Mind and Brain: Analyzing Developmental Pathways of Learning
Disorders,” by K. W., Fischer, L. T. Rose, and S. P. Rose, in Mind, Brain, and Education in Reading Disorders, K. W. Fischer,
J. H. Bernstein, & M. H. Immordino-Yang (Eds.), in press, Cambridge, England: Cambridge University Press; From “Learning
to Read Words: Individual Differences in Developmental Sequences,” by C. C. Knight and K. W. Fischer, 1992, Journal of Ap-
plied Developmental Psychology, 13, pp. 377–404.
Word Definition
Reading
Production
Rhyme
Production
Reading
Recognition
Rhyme
Recognition
Letter
Identification
Word Definition
Reading
Production
Rhyme
Production
Reading
Recognition
Rhyme
Recognition
Letter
Identification
Word Definition
Reading
Production
Rhyme
Production
Reading
Recognition
Rhyme
Recognition
Letter
Identification
(a)
(b)
(c)
main pathway (a), but poor readers showed two other
pathways different from the normal one (b and c).
This map of alternative pathways suggests a different
remedial educational strategy. Instead of attempting to
speed up development in poor readers, teachers can help
channel children following divergent pathways into al-
ternatives that converge on the goal of skilled reading
(Fink, in press; Wolf & Katzir-Cohen, 2001). By provid-
ing environmental support, teachers can channel devel-
opment, building bridges from the known to the
unknown instead of providing frustrating repetitive en-
counters with the unknown. This approach is being real-
ized most fully in educational efforts for children with
learning disorders and handicaps (Fischer, Bernstein, &
Immordino-Yang, in press; Rose & Meyer, 2002) and
also in some work with maltreated and aggressive chil-
dren (Ayoub & Fischer, in press; Kupersmidt & Dodge,
2004; Watson, Fischer, & Andreas, 2004).
From this perspective, the tool of mapping alternative
developmental pathways is especially important for the
study of development among children of differing so-
cioeconomic groups, cultures, ethnicities, or races, and
children with learning or psychological disorders.
Against the backdrop of a developmental ladder based on
White, middle-class norms, children from different so-
cial groups are frequently seen as exhibiting deficits in
development. Within the web metaphor, many develop-
mental differences become alternative pathways instead
of deficits, and curricula, interventions, or therapies can
be created based on these alternative pathways.
Research methods should allow detection of alterna-
tive sequences instead of forcing all children to either fit
or not fit one sequence. Remarkably, much research on
development has treated sequences not as variable phe-
nomena to be explained but as fixed milestones in a lad-
der. In the early 1970s, Flavell (1971) and Wohlwill
(1971) called for more research on variation in se-
quences, but this call has only recently begun to be taken
seriously. Most neo-Piagetian developmental theories and
domain theories still differentiate only gross stages, ig-
noring completely branches in sequences and variations
among steps, with a resulting overgeneralization of the

Page 25
336 Dynamic Development of Action and Thought
uniformity and universality of cognitive and emotional
development.
In summary, the organization of human action,
thought, and emotion shows wide, systematic variation
that can be measured, analyzed, and explained in hierar-
chically organized systems of contextually embedded
activity. Patterns of variation in developmental level,
synchrony, and sequence are all consistent with a con-
structivist, dynamic systems interpretation of psycholog-
ical structure. In light of the pervasive evidence of
cognitive variability, it seems surprising that the most
prominent models of psychological structure have been
and continue to be based on static conceptions such as
stage, competence, and innate core knowledge. To under-
stand why these static conceptions of structure continue
to dominate and how dynamic views of psychological
structure move beyond them, we consider the history
and origin of static conceptions of psychological struc-
ture and their shortcomings as explanatory tools in the
next section.
THE CRISIS OF VARIABILITY AND THE
CARTESIAN SYNTHESIS IN
DEVELOPMENTAL SCIENCE
The failure of developmental theory to recognize the
dynamic and constructive nature of psychological
structure has led to an explanatory crisis in develop-
mental science. At the heart of this crisis is the problem
of how to account for the tremendous variability in de-
velopmental phenomena, which during the past 30
years has increasingly moved from the background to
the foreground of developmental research and theory
(Bidell & Fischer, 1992; Damon, 1989; Siegler, 1994,
Chapter 11, this Handbook, Volume 2; Thelen & Smith,
Chapter 6, this Handbook, this volume).
The static stage structure, which dominated theories
of cognitive development from its inception through the
early 1980s, proved incapable of accounting for the mas-
sive evidence of (a) both wide-ranging variation and
sometime consistency within and across individuals in
the age of acquisition of logical concepts across domains
and contexts, (b) systematic sequences in acquisition of
many of these concepts and their components, and (c)
variation from high to low synchrony in development of
concepts under various conditions. By the mid-1980s,
the inability of stage theory to account for this combina-
tion of variability and consistency led many scholars to
virtually abandon stage theory as a framework and to
launch a series of alternative accounts of psychological
structure and its origin.
Many of these alternative accounts attempt to explain
variability without departing from the static structure-
as-form metaphor, but they have consistently come up
short. Traditional Piagetians tried to package up vari-
ability in the concept of “decalage,” which simply
means a gap in ages of acquisition across tasks or indi-
viduals, and then mostly ignored it, thus renaming vari-
ability but not explaining it. Other theorists introduced a
separation between competences or underlying struc-
tures that remain static and performances or surface
manifestations that can vary. However, the separation of
action from competence in competence-performance
and nativist models introduces a major mystery about
what interferes with the expression of competence and
creates an inability to explain how psychological organi-
zation directs action and how structures adapt to a range
of environmental and cultural contexts.
Why do developmental theorists cling to static struc-
tural models? The most important reason, we propose,
is the pervasive influence of the Cartesian epistemolog-
ical tradition in the history of Western psychological
thought (Descartes, 1960; Gottlieb, Wahlsten, & Lick-
liter, Chapter 5; Overton, Chapter 2; Valsiner, Chapter
4, this Handbook, this volume). The Cartesian method
conceptually isolates mental systems from their natural
context of interrelations with the biological and cultural
systems of which they are a part. This intellectual
methodology of isolating an object of study from inter-
relationships with other phenomenon was successful in
the early history of the natural sciences, but it obscures
the complexity and dynamism of mental activity. It
leads to systematic distortions when applied to the ques-
tion of mental organization or psychological structure.
In this section, we review the Cartesian framework
and the empirical debate surrounding the concept of
“stage structure,” showing how this debate led to the
discovery of variability in level, synchrony, and se-
quence, and why the formal view of structure was un-
able to predict or explain this variability. We then argue
that three major theoretical movements since stage
theory—(1) domain specificity theory, (2) nativist com-
petence theory, and (3) competence/performance the-
ory—have also proved inadequate in accounting for
variability in structural development because they too
have failed to move beyond the Cartesian structure-

Page 26
The Crisis of Variability and the Cartesian Synthesis in Developmental Science 337
as-form paradigm. In the subsequent section, we de-
scribe a set of methods for moving beyond these ap-
proaches to do research that deals with variability more
powerfully within a dynamic structural framework, in-
cluding an outline of how to turn theories about develop-
mental process into specific mathematical models that
can be tested against growth patterns of individual chil-
dren and adults.
The Cartesian Dualist Framework
The debate over nature-versus-nurture explanations of
the origin of knowledge assumes the Cartesian frame-
work, which is accepted by both sides—nature/nativist
and nurture/empiricist. Grounded in the dualism of
mind and world, the two sides necessarily imply one
another. The nativist-rationalist tradition and the
empiricist-learning tradition are two sides of the same
Cartesian coin. The nativist branch of the Cartesian
framework explains the origin of psychological struc-
ture as preformed innate structures such as concepts.
The empiricist branch explains it as experience stamp-
ing its shape on the natural mind. Psychological struc-
ture, conceived as innate form, implies some outside
input to be stored and manipulated. Environmental in-
formation conceived as preexisting packets of knowl-
edge requires some sort of preexisting receptacle or
organizing structure in the mind to receive, contain,
and organize them. In this framework, only two expla-
nations for the origin of psychological structure seem
possible—nature or nurture—and they become the
basis for the two branches of Cartesian epistemology.
The Cartesian tradition in philosophy and science
brings with it the methodologies of reduction and reifi-
cation. These methods, which have been profitably em-
ployed in many areas of science, result in systematic
misconceptions when applied to dynamic processes like
development of action, thought, and emotion. The dy-
namic organization of human mental activity is ab-
stracted from the living systems of which it is a property
and treated as a separately existing “thing,” giving birth
to the conception of static structure. The reification of
psychological structure as a separately existing static
form leads scientists down false paths in trying to un-
derstand the origins and development of psychological
organization. Instead of seeking to understand the con-
structive, self-organizing processes by which children
build new relations among contextually embedded men-
tal activities, theorists have been led into the futile
nature-nurture debate about whether statically con-
ceived psychological structure is somehow insinuated in
the genome or is built up through analysis of perceptual-
motor experience. These reductionist assumptions sup-
port static views of structure and limit the explanatory
power of developmental theories.
The Cartesian method, emerging in the seventeenth
century philosophy of Ren� Descartes (1960) and oth-
ers, gave science a powerful analytical tool to sort out
the complexity of the world and focus on one aspect at a
time for study. This tool, known as Cartesian reduction-
ism, derives simplicity out of complexity by isolating
one aspect of a process from its relations with other as-
pects of the process or from related processes, to be
studied independently. Descartes tried to extract mind
from nature by creating a dualism in which a separately
existing mental structure receives impressions from
the outside world through the sensory apparatus.
Descartes’s famous dissection of the cow’s eye, reveal-
ing the image projected on the retina, supported his
view that innate structures are fed with sensory images
from the environment. Similarly, in his logical empiri-
cism the philosopher John Locke (1794) asserted that
some preexisting logical structure is required to explain
how environmental input leads to higher order knowl-
edge. Locke saw that the simple mechanism of associa-
tion of sensory impressions could not account for
higher-order knowledge involving induction, deduction,
and generalization. Like Descartes, Locke’s account of
knowledge acquisition involved a dualist conception in
which a preexisting psychological structure receives and
processes sensory input from the outside.
Although Cartesian reductionism has been and will
continue to be an indispensable tool of scientific analy-
sis, its strength—the isolation of phenomena from com-
plex relations—is also its weakness (Wilson, 1998).
When Cartesian reductionism is used exclusively as an
analytic method, it eliminates an essential characteris-
tic that needs to be understood—the interrelations of
psychological systems both internally among component
processes and externally with other systems. Under-
standing relations is a requisite for understanding
change and variation in developmental or historical phe-
nomena. In the real world, it is the interrelations among
systems and processes that effect movement and
change. The gravitational relation between the earth
and the moon is key to sustaining the moon’s orbit,
which generates the changing cycles of the moon seen
on earth. To ignore the gravitational relation between

Page 27
338 Dynamic Development of Action and Thought
earth and moon would preclude understanding the
source of this pattern of variability, and in turn its ex-
planation of an orbital system. The reductionist ap-
proach can be highly efficient for restricted scientific
purposes such as isolating a particular strain of bacteria
that causes a human disease. It is problematic in study-
ing any complex phenomenon involving relations among
elements and systems such as the problem of how some
bacteria evolve more virulent strains in the modern con-
text of changing natural and social ecology, growing
poverty and hopelessness in many locales, and overuse
of antibiotics. The structure grows dynamically out of
the relations among varying systems, neither from a
static innate structure nor a static environmental struc-
ture stamped on the mind.
The exclusive use of reductionism as an analytical
method fosters the related problems of reification and
dualism, both arising from the neglect of relations in
theoretical constructs. Without an account of the rela-
tions among systems that can explain movement and
change, abstractions such as mind, thought, and struc-
ture appear static and isolated from other constructs
such as body, action, or function. These static abstrac-
tions reify the phenomena they refer to, treating dy-
namic processes as frozen objects. The self-organizing,
goal-directed activity of the human agent is ruled out of
the accounts of development.
Moreover, because the relations between such reified
processes are lost, they seem isolated, separate, and
even opposite to one another. This seeming opposition
of reified abstractions is the basis for the classic Carte-
sian dualisms separating mind from body, thought from
action, and structure from function. Since the time of
Descartes, such dualist assumptions have become in-
grained in the mainstream of Western scientific thought
in general and psychological theories in particular. The
result has been static accounts of psychological phenom-
ena and their origins and sterile debates that explain
mental processes by one or another reified abstraction
such as faculties, associations, stimulus-response bonds,
innate concepts, or stages. While such single-construct
explanations have generated intense debate, they have
been notoriously limited in accounting for a broad range
of developmental data.
The Tacit Modern Synthesis in Psychology: Nativism
and Empiricism Together
The result of the debate that has continued for more than
a century between empiricist and nativist theories of de-
velopment is the emergence of a tacitly shared model—a
kind of modern synthesis in psychology—that is neither
strictly empiricist nor strictly nativist but simply Carte-
sian in its assumptions. The emerging model is an amal-
gam of a sort of logical empiricism with a version of
maturationism. According to this view, infants are sup-
plied innately with core knowledge systems that provide
them with predetermined representations of certain as-
pects of the world such as numerosity and object perma-
nence (Carey & Spelke, 1996; Hauser, Chomsky, &
Fitch, 2002; Spelke, 2000). However, these initial repre-
sentations must be extended by learning processes.
Learning processes typically are characterized through
a logical analysis of perceptual-motor input leading to
inductions and generalizations growing from core
knowledge. Debate continues about whether core knowl-
edge systems change qualitatively over time or simply
remain in place into adulthood, which mechanisms lead
from innate representations to new forms of knowledge,
and what roles perceptual analysis and learning mecha-
nisms play in such changes. Yet the framework of the de-
bate remains firmly grounded in Cartesian assumptions.
With respect to the origins and development of knowl-
edge, the debate between empiricism and nativism—and
the emerging modern synthesis—starts with a core set of
shared dualist assumptions: The mind is isolated from its
environmental context, thought is divided from action,
and the way the mind is organized (psychological struc-
ture) is separated from the way it operates in the world
(cognitive function).
Early empiricists tried to explain the origins of
knowledge in sensory impressions of the environment
with little reference to the role of the active person and
mind. In classic empiricist theories, the role of organi-
zation in the mind is minimal (a “blank slate” in the
extreme), and it is shaped by environmental contingen-
cies. Links or associations between ideas are generated
by whatever happens to co-occur: A person sees red
and apple at the same time, so she or he remembers red-
apple. In the behaviorist version of associationism, the
mind is reduced to almost no role at all, and behavior is
organized directly by environmental contingencies
through the stimulus-response bond (Skinner, 1969).
Contemporary empiricist theories tend to rely on an in-
formation processing metaphor in which sensory infor-
mation from the environment is parsed by perceptual
analysis into basic knowledge units that can then be
recombined into higher level knowledge (Newell &
Simon, 1971). However, common to all empiricist theo-
ries of mental development is a dualist separation of

Page 28
The Crisis of Variability and the Cartesian Synthesis in Developmental Science 339
mind from environmental context, a concomitant reifi-
cation of the mind as a container or mechanistic
processor, and a dualist separation of mental structure
from mental content.
Information processing theories, in the empiricist
tradition, have focused on the input and storage of infor-
mation, building the analysis of cognitive structure on a
model of information flow in a computer. These theo-
ries came late to the problem of where cognitive struc-
tures come from and how they change over time. A few
information processing theories have posited qualitative
hierarchies of cognitive structures (Anderson et al.,
2004; Klahr & Wallace, 1976; Pascual-Leone, 1970),
but they have provided only sketchy accounts of the ori-
gins of these structures and the mechanisms of transi-
tion from one structure to another.
Despite years of vociferous debate with empiricists,
nativists share this set of dualist assumptions but privi-
lege them in different ways (Fischer & Bullock, 1984;
Overton, Chapter 2, this Handbook, this volume). Na-
tivists and the closely associated rationalists also start
from an acceptance of mind-environment, mind-body,
and thought-action dualisms. The difference with em-
piricists is that the structure of the mind is primary in-
stead of the structure of the environment. Nativists
accept the dualism of inner structure and outer sensory
information, but they simply assign them different roles.
Instead of filling up preexisting mental containers with
experience, the nativist role for sensory information is
to provide inputs, which trigger the emergence or activa-
tion of preexisting psychological structures such as the
syntax of language or the properties of objects. The du-
alist separation of psychological structure from its con-
textual relations with human activity has led to the
reification of psychological structure and the inevitable
conclusion that the structure must be innate. The outside
world provides grist for the cognitive mill, or sometimes
a triggering stimulus to kick off a new level of matura-
tion, but plays a minimal role in the development of the
psychological structures themselves.
When a dynamic system is approached statically, the
complex relations by which it is organized and by which
it develops are lost. The inescapable fact that it is organ-
ized is abstracted and reified as static form. When psy-
chological structure is conceived as static form, with no
activity and no inter-systemic relations to explain its
origin and development, it appears to have an existence
of its own, separate from the reality from which it is ab-
stracted. Therefore, psychological structure must be in-
nate, according to this argument.
The reification of dynamic structure as static form in
the Cartesian tradition has earlier roots in Western cul-
ture (Pepper, 1942) extending back at least to Plato
(1941) 2,000 years ago. His doctrine of ideal, universal
forms provides a particularly clear example of how
concepts and ideas are seen as independent of the mind.
These forms exist independently of the imperfect
material world, which evolves toward them. They are
transferred to each newborn infant, who gradually re-
members them with maturity. In the eighteenth century,
Kant (1958) argued that we inherit preexisting cognitive
structures or categorical imperatives, which determine
how we make sense of our experience. In recent times,
Chomsky (1965) and Fodor (1983) have argued for pre-
determined linguistic structures called modules that im-
pose specific patterns on our learning of languages and
concepts. Following Chomsky’s lead, contemporary
neo-nativists have posited innate structures determining
such developmental achievements as number concept,
object concept, and Euclidian geometry (Baillargeon,
1987; Fodor, 1983; Spelke, 1988).
Because both the empiricist and the nativist versions
of the Cartesian tradition share the same dualist, static
conception of psychological structure, neither has really
challenged the other on the nature of psychological
structure. However, the debate over how much emphasis
to place on innate structures versus learning has forced
each side to examine, rethink, and revise its theories. As
theorists on both sides of the empiricist-nativist debate
have attempted to revise their models to meet these
challenges they have naturally turned to models within
their shared Cartesian framework, and thus have in-
creasingly adopted elements of each other’s theories.
While still emphasizing the importance of perceptual
input, empiricism-based theories have come to rely on
nativist conceptions about the origins of psychological
structure to help explain how that input gets organized
and how its organization changes over time. On the na-
tivist side, theorists have increasingly come to depend
on various functional-learning and perceptual-analysis
mechanisms to explain how innate structures can lead to
knowledge and conceptual change.
At first glance, bringing together two opposing ten-
dencies into a more integrated model may seem like
progress toward a more comprehensive theory. The re-
sulting amalgamated model, however, does not take us
beyond the Cartesian framework of dualism and there-
fore does not offer a way beyond the static conceptions
of psychological structure—a way to explain how struc-
ture emerges from the interrelated activity of people

Page 29
340 Dynamic Development of Action and Thought
with their world and each other. For this reason, the
Cartesian synthesis is not any more successful in ex-
plaining the broad data of variability in cognitive devel-
opment. Linking static conceptions of psychological
structure to mechanistic information processing models
does not provide us with better explanations for variabil-
ity in cognitive performance than either tradition did on
its own. Understanding why Cartesian models—
whether empiricist, nativist, or a combination of the
two—have trouble explaining variability requires con-
sidering in more depth the static conceptions of psycho-
logical structure inherent in this tradition and the
explanatory limitations they carry with them. This
analysis lays the foundation for understanding how dy-
namic structuralism provides a path to analyzing the dy-
namics of structure in development starting from
activities in context.
The Structure-as-Form Paradigm
Because the Cartesian tradition has been the dominant
framework for scientific theories in general and psycho-
logical theories in particular, reductionism and reifica-
tion have been the rule rather than the exception in
conceptions of psychological structure. The prominence
of these modes of thought in the Western intellectual tra-
dition has encouraged the confounding of dynamic struc-
ture with static form. Accordingly, the structure-as-form
model has tended to serve as an unconscious founda-
tional metaphor (Lakoff & Johnson, 1999; Pepper, 1942)
or paradigm (Kuhn, 1970) for scientific accounts of the
organizational properties of natural and social systems,
especially in psychology (Overton, Chapter 2; Valsiner,
Chapter 4, this Handbook, this volume).
It is no easy matter to move beyond the static
metaphors for structure, which language and cultural
practices strongly support and which people typically
use unaware. A dramatic, pervasive example is the con-
duit metaphor for communication (Lakoff & Johnson,
1980; Reddy, 1979). In ordinary discourse about com-
munication of knowledge, people use this metaphor,
talking as if the mind is a container for knowledge and
as if things that they know are discrete objects. They
treat communication as the transfer of knowledge ob-
jects from one person to another, as if static objects are
being sent through a conduit such as a pipe or telephone
line. This metaphor often leads to the belief that telling
someone an item of information (giving them an object)
is sufficient to communicate it and even to teach it. If a
course or a chapter covers a concept, for example, then
the student or reader is assumed to have been given that
object. If they fail to demonstrate the knowledge speci-
fied by that object, they are taken to be ineffective
learners (stupid, inattentive, or lazy). Research shows
that students do not learn effectively from such presen-
tations, but they require experience with acting on
and manipulating the material to understand it (Crouch,
Fagen, Callan, & Mazur, 2004; Schwartz, 2000;
Schwartz & Fischer, 2005). This static metaphor (and
others as well) omits the constructive nature of learn-
ing, knowing, and understanding from the assumed
structure of communication and education, and their so-
cial nature is minimized too.
The conceptualization of structure as form treats
structure as a static property of knowing that can be
separated from the knowing activities themselves, just
as the conduit metaphor separates objects of knowledge
from activities of knowing. Imagine trying to remove
the structure from the Golden Gate Bridge, gather it up
somehow, and ship it off to someone else, who would
add it to a pile of steel, which would quickly arise to
form a replica of the San Francisco landmark. Even
more absurd would be trying to extract the structure
from the tightly coordinated, self-organizing, physico-
chemical processes of a living cell and then to apply it
to a blob of inert chemical components in hope of gener-
ating a new cell. Structure is an inseparable quality of
real dynamic systems, and it emerges as they develop
(are constructed). In reality, structure cannot be sepa-
rated from its role as the organizational property of dy-
namic systems.
In the study of development, three static conceptions
of psychological structure have predominated, all of
which have used static forms to explain dynamic struc-
tures. In many developmental theories, including Pi-
aget’s (1983, 1985) stage theory, activities take the form
of abstract logical structures. In many linguistic and
cognitive theories, activities take the form of preformed
quasi-logical rules, typified by Chomsky’s (1957, 1995)
theory of innate linguistic competences and its corollary
theories of innate cognitive competences (Baillargeon,
1987; Fodor, 1983; Spelke, 1988). In many traditional
empiricist theories in Anglo-American psychology, ac-
tivities take the form of linear input-output rules, as
typified by linear models in statistics, information pro-
cessing, and behavior genetics (Anderson et al., 2004;
Horn & Hofer, 1992; Plomin, DeFries, McClearn, & Rut-
ter, 1997). This linear form of theory is especially
prominent in approaches that focus on domain speci-

Page 30
The Crisis of Variability and the Cartesian Synthesis in Developmental Science 341
ficity, the separation of knowledge into distinct parts
tied to domains of experience.
Despite well-publicized disagreements among these
three frameworks, they derive their core assumptions
from the structure-as-form paradigm, portraying psy-
chological structure in abstract forms existing sepa-
rately from real self-organizing human activities. In
stage theory, psychological structure is seen as a univer-
sal abstract logic imposing itself on the developmental
trajectories of every person. Although Piaget believed
that activity is the basis of knowledge and development,
the base metaphor for his stage theory of cognition is
successive stages of logic that determine specific cogni-
tive performances across contexts and domains of
knowledge and are relatively unaffected by the contexts
of those performances. Similarly, nativist competence
theories project a universal preformed code, blueprint,
or set of instructions that somehow exists separately
from the activities that it will someday engender. Like
Platonic forms, these blueprints lurk among the genes,
awaiting the right moment to impose order on behavior.
The experimental/psychometric framework also
bases its core assumptions on structure as form, but
there the structure is hidden behind standard methods
and paradigms for explanation. The assumed linear
combinatorial structures of dichotomies—person and
environment, input and output, heredity and experi-
ence, domain x versus domain y—are embedded in re-
search designs, statistical techniques, and theoretical
concepts, but their implicit assumptions about structure
are seldom acknowledged (Bronfenbrenner, 1979; Fis-
cher & Bullock, 1984; Gottlieb, Wahlsten, & Lickliter,
Chapter 5; Overton, Chapter 2; Thelen, & Smith, Chap-
ter 6; Valsiner, Chapter 4, this Handbook, this volume;
Wahlsten, 1990; Wittgenstein, 1953). Person and envi-
ronment are partitioned into separate groups of factors
instead of being treated as dynamic collaborators in
producing activities. Much of modern biology has
assumed similar reductionist, reifying notions of struc-
ture as form (Goodwin, 1994; Gottlieb, 2001; Kauff-
man, 1996).
The dominance of the structure-as-form paradigm in
cognitive developmental theory has forced scholars to
choose among these three inadequate notions of struc-
ture—stages, innate structures, and linear information
processes. Instead, structure needs to be conceived dy-
namically. Psychological structure exists as a real orga-
nizational property of dynamic systems, just as the
structure of the human skeletal system and the human
circulatory system are real and distinguish humans from
other animals. The structure is a property of the self-
organizing systems that create it—the dynamic organi-
zation exhibited by self-organizing systems of mental
and physical activity, not a free-floating ghost of compe-
tence or logic that dictates behavior to its human ma-
chine. Before we explicate concepts and methods of
dynamic structure, however, we need to ground our ar-
gument with analysis of key problems with the static
conceptions of structure that pervade developmental
and psychological science.
The Stage Debate and the Discovery of
Variability in Cognitive Development
The strength of the stage structure concept, as with all
structure-as-form models, is its account of stability in
development. Skills exhibit patterns of stability both in
the ways they function and the ways they develop. What
would account for such stable patterns in the functioning
and development of cognition? Piaget’s (1983, 1985)
conception of formal logical stages addressed this ques-
tion with what seemed to be a powerful and reasonable
explanation: Individuals construct logical structures
that preserve the organization of their interpretive or be-
havioral activities to be applied again at later times or in
different situations. The existence of these structures
accounts for the ability to apply the same concept or
skill across many situations. Similarly, the emergence of
concepts in specific sequences is accounted for by the
fact that the logical structures underlying the concepts
are constructed gradually, so that a partially complete
logic would give rise to one concept (e.g., one-to-one
correspondence) and the later completion of the logical
structure would give rise to a more extensive and logi-
cally complete concept (e.g., conservation of number).
Piagetian stage theory places all human cognitive activ-
ities into a sequence of abstract logical forms, but it has
proved incapable of explaining the vast array of devia-
tions from stage predictions (Bidell & Fischer, 1992;
Flavell, 1971; Gelman & Baillargeon, 1983).
However, the strength of the stage structure concept
was also its greatest weakness: Whereas universal logical
structures accounted elegantly for stability, they offered
hardly any explanation for variability in the functioning
and development of cognition. Because the stage concept
equated psychological structure (the organization of dy-
namic mental activity) with static form (formal logic), it
provided no model of the real psychological mechanisms
that might lead to variability and change in development.
The idea of a fixed logical structure underlying all of a

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342 Dynamic Development of Action and Thought
child’s conceptions at a given stage seems to explain ob-
served consistencies in the form of children’s thinking,
but it predicts much, much more consistency than chil-
dren show, and it has proven incapable of explaining de-
partures from the predicted consistency.
Departures from the consistency predicted by stage
theory proved to be more the norm than the exception as
proliferating replication studies introduced a myriad of
variations on Piaget’s original tasks and procedures. On
the one hand, opponents of Piaget’s theory, doubting the
reality or usefulness of formal stage structures, focused
their research on identifying conditions in which stage
theory predictions failed. In contrast, supporters of
Piaget’s constructivist view tried to validate the pur-
ported products of development—stage sequences, tim-
ing of cognitive achievements, and universality. These
researchers focused a great deal of attention on demon-
strating conditions in which stage predictions were
empirically supported. Today, many researchers still
continue along these independent paths, mostly ignoring
or dismissing findings of people from the other camp.
The outcome of this protracted and often heated em-
pirical debate has been the discovery of remarkable vari-
ability in every aspect of cognitive development studied.
As researchers implemented variations in the nature of
task materials, complexity of tasks, procedures, degree
of modeling, degree of training, and methods of scoring
across a multitude of replication studies, a consistent
pattern of variation emerged (Bidell & Fischer, 1992;
Case, 1991b; Fischer, 1980b; Halford, 1989; Louren�o
& Machado, 1996). To the extent that studies closely ap-
proximated the assessment conditions used by Piaget,
the findings were similar to those he had reported. When
tasks and procedures varied greatly from Piaget’s, the
findings also varied greatly within certain limits.
A classic example of this pattern of variation is found
in research on number conservation. In Piaget’s theory,
number conservation (the ability to conceptually main-
tain the equality of two sets even when one set is trans-
formed to look much larger than the other) was seen as a
product of an underlying stage of concrete operational
logic. In the original number conservation studies, Pi-
aget and Szeminska (1952) had used sets of 8 or 10 ob-
jects each and had identified 6 to 7 years as the typical
age of acquisition for this concept. In one group of repli-
cation studies, Gelman (1972) showed that the age of ac-
quisition for number conservation could be pushed
downward from Piaget’s norms if the task complexity
was simplified by (a) reducing the size of the sets chil-
dren had to compare and (b) eliminating the requirement
for verbal justification of conservation judgments.
Under these conditions, Gelman reported that children
as young as 3 to 4 years of age could answer conserva-
tion questions correctly. Fortunately, the debate about
number eventually produced important new discoveries
spelling out developmental pathways for the early con-
struction of number actions and concepts (Case et al.,
1996; Dehaene, 1997; Spelke, in press).
As replication studies proliferated, this seesaw de-
bate over age of acquisition of logical concepts was ex-
tended to other dimensions of psychological structure
where researchers produced similar patterns of variabil-
ity as a function of assessment conditions. These in-
cluded variability in the three central characteristics we
have described (developmental level, synchrony in level
across domains or contexts, and sequence of develop-
ment in a domain or context).
The growing empirical documentation of variability
in development posed severe problems for the concept of
formal stage structures. If concepts such as conserva-
tion of number are supported by underlying logical
structures, then why wouldn’t the logical structure man-
ifest itself in most if not all situations? Why would a
child show logical thinking one moment and in the next
moment, appear to have lost it? If cognitive development
consists of the emergence of successive forms of under-
lying logic, why wouldn’t developmental sequences re-
main the same across domains, contexts, and cultures?
The formal concept of stage structure could offer no
specific explanation for this pattern of variability, but
only the label of decalage.
In one sense, victory in the stage debate went to the
skeptical. By the mid-1980s, the inability to account for
the dramatic departures from stage theory’s predictions
of cross-domain, cross-individual, and cross-cultural
consistency had resulted in a general flight from stage
theory as an explanatory framework (Beilin, 1983). In a
more important sense, however, there was no winner be-
cause neither side had offered a workable explanation of
the patterns of variation the debate uncovered. What
concept of psychological structure would explain the
fact that cognitive performance varies so greatly with
changing conditions and yet also exhibits great consis-
tency under other conditions?
Explaining Variability versus Explaining It Away
From the perspective of the history of science, one
might think that the discovery of new patterns of vari-
ability would be met with excitement and theoretical ad-

Page 32
The Crisis of Variability and the Cartesian Synthesis in Developmental Science 343
vance. After all, a central task of science is to discover
and account for variability. Theories are constructed
and reconstructed to interpret the range of variation ob-
served and to search for patterns of order within this
range. Indeed, an essential criterion of sound scientific
theories is that they account for the full range of vari-
ability observed in a phenomenon of interest.
However, change in scientific theories is rarely that
simple. Evidence that threatens a prevailing worldview
or paradigm can lead to attempts to assimilate the dis-
crepant findings into the current paradigm, either by
denying their relevance or by advancing alternative
explanations within the dominant paradigm (Hanson,
1961; Kuhn, 1970). Responses to the discovery of vari-
ability in development have followed this pattern, re-
turning to the prevailing Cartesian framework and
building minor modifications to account for portions of
the observed variability. Instead of attempting to fully
describe the range of variability and explain the reasons
for the observed patterns, responses have tried to ex-
plain away variability through a variety of theoretical
maneuvers that include ignoring variability, accepting
variability without explaining it, and focusing on se-
lected effects of variability to support existing theory
with minor adaptations. Each of these theoretical re-
sponses to variability has served to preserve some
version of the Cartesian framework and the structure-
as-form paradigm in the face of the new evidence and
has led to the modern Cartesian synthesis, despite the
fact that most of the evidence of variability remains
unexplained.
Reasserting Stage Theory
Piaget, Kohlberg (1969), and other stage theorists at
first mostly ignored variability, treating it basically as a
nuisance or as error of measurement. Differences across
domains, tasks, contexts, and coparticipants in phenom-
ena such as age of acquisition, synchrony, and develop-
mental sequence were said to represent varying forms of
resistance to the operation of underlying logical struc-
tures. Although Piaget later acknowledged the inade-
quacy of this position and experimented with alternative
logic frameworks (Piaget, 1985, 1987; Piaget & Garcia,
1991), he never found an alternative concept of struc-
ture that would predict and explain when and how
performance varies. (The discovery of the scale of hier-
archical skill levels, shown in Figure 7.3, came from
analyzing patterns of variation in growth curves,
demonstrating the usefulness of analyzing variation for
understanding stages.)
Several scholars have emphasized Piaget’s belief in
the importance of decalage and other forms of variation
(Beilin, 1983; Chapman, 1988; Louren�o & Machado,
1996), but recognizing that phenomena need to be ex-
plained is not the same as explaining them. Piaget and
other stage theorists have not specified the processes by
which cognitive stage structures and environmental re-
sistance interact to make one kind of task develop later
than another in general. They have dealt even less ade-
quately with variations across individuals in the order
and timing of acquisition of skills and variations within
an individual related to tasks, context, social support,
and experience. In short, stage theory has provided no
explanation for most observed patterns of variation in
developmental level, synchrony, and sequence (Bidell &
Fischer, 1992; Edelstein & Case, 1993).
Domain Specificity Theory
As evidence of variability grew and the inadequacy of
the classic stage concept became clear, the theoretical
crisis deepened. With stage theory losing its potential to
generate interesting and credible research and with no
clear alternative model of psychological structure avail-
able except for Chomskian nativism, some framework
was needed as a basis for the continued empirical study
of development. Domain specificity theory emerged as a
way of freeing the field from its dependence on stage
theory without demanding a new commitment to any
particular model of psychological structure. According
to domain specificity theory, psychological processes
are not organized in universal structures, but within lim-
ited domains such as spatial, linguistic, or mathematical
reasoning, or for groups of similar tasks such as problem
solving, analogical reasoning tasks, and theory of mind
(Demetriou, Christou, Spanoudis, Platsidou, 2002;
Hirschfeld & Gelman, 1994; Turiel & Davidson, 1986;
Wellman, 1990). The structures in these domains are
often referred to as modules, indicating separate, dis-
tinctive structures of brain and behavior (Fodor, 1983).
In education, domain specificity became a major theme
through the influence of Howard Gardner’s (1983) the-
ory of “multiple intelligences,” leading to curricular re-
visions in schools around the world.
Description of development and learning within im-
portant domains has great value for both developmental
science and education, but many scholars have stopped
with the domain description. They thus avoid having to
explain patterns of variability—for example, the differ-
ences and similarities in age of acquisition across dif-
ferent logical concepts such as number and theory of

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344 Dynamic Development of Action and Thought
mind. Instead, they simply assert that cognition is or-
ganized locally and so cross-domain relations do not
have to be explained. This theoretical stance simply ac-
knowledges the fact of variability and sidesteps a sys-
tematic account of its origins.
In some ways, this acknowledgment has represented
an advance for a field once dominated by stage theory
with its assumption of a single logic that catalyzes
change across all aspects of the mind. However, to the
extent that domain specificity creates the illusion of
having solved the problem of variation, it is an unfortu-
nate theoretical detour. Developmental scientists need
to explain why clusters of many (structurally equiva-
lent) concepts emerge in different domains around the
same time, showing interval synchrony (Case, 1991b;
Fischer & Silvern, 1985). They need to explain how an
individual who is working within a single domain and
task exhibits one skill level when working alone, but a
distinctly higher level when working with the support of
a helpful adult (Fischer, Bullock, et al., 1993; Rogoff,
1990). Although domain specificity theory provides im-
portant recognition of developmental variability, it of-
fers no explanation of variability across domains and
within individuals.
Neo-Nativism
An important response to the evidence of variability has
been the neo-nativist movement (Carey & Gelman,
1991; Fodor, 1983; Spelke, 1988), which represents a
major theoretical alternative to stage theory within the
structure-as-form paradigm. Researchers taking this
perspective have used ingenious experiments to uncover
surprising capacities of infants and young children and
have led to the creation of the modern Cartesian synthe-
sis. With the rejection of the concept of structure as
stages of formal logic, the other predominant concept of
structure—innate formal rules—seems to be the only
remaining alternative within the structure-as-form par-
adigm. Unfortunately, the concept of innate formal rules
has the same fundamental limitation as its sister concept
of formal logic: As a static conception of structure, it
cannot adequately account for the variability that arises
from dynamic human activity (Fischer & Bidell, 1991).
Neo-nativist researchers have focused on selected ef-
fects of cognitive variability that seem to support the
existence of innate competences within prominent do-
mains such as number, space, language, object proper-
ties, and theory of mind (Carey & Spelke, 1994). For the
most part, they have not attempted to deal with the ex-
tensive variability found in performance. Indeed, the
modern father of this movement, Noam Chomsky (1965,
1995), specifically rejects the evidence of variability in
language, asserting that it is illusory and that all people
“really” speak the same fundamental language. The
Chomskian theory of linguistic competence accounts for
human linguistic behavior on the basis of a set of innate
rules, only a few of which have been specified. Despite
almost 50 years of effort, nativism has been notoriously
unable to account for either the variations of human lan-
guages (Chinese is different from English!) or the highly
variable everyday communication skills that individuals
develop in a language within and across diverse settings
(Lakoff, 1987; Ninio & Snow, 1996; Slobin, 1997). Nev-
ertheless, the nativist approach has had great appeal to
many developmental scientists because of its important
discoveries about children’s early abilities.
The basic paradigm for neo-nativist research is to de-
sign tasks that drive ages of acquisition much lower than
traditional Piagetian norms (Baillargeon, 1987; Spelke,
1988, in press). Nativist researchers introduced tech-
niques for simplifying Piagetian task materials and pro-
cedures, requiring only minimal activity from a child or
providing modeling, training, and other forms of sup-
port for more complex activity. They have shown great
ingenuity in discovering capacities of young infants and
children, demonstrating strong violations of Piaget’s
age norms for various logical concepts. Their neo-
nativist argument is that cognitive structure must be in-
nate because acquisition of certain concepts can be
demonstrated at very young ages. However, this argu-
ment from precocity takes into account only half the evi-
dence for variability—the downward half (Fischer &
Bidell, 1991; Halford, 1989). It treats the earliest age as
the “real” age for a concept’s emergence, ignoring evi-
dence of wide variations in age of acquisition both up-
ward and downward.
A good example of the focus on early age instead of
variation is the extensive research on infants’ acquisition
of knowledge of objects, especially object permanence
(objects continue to exist even when they have been dis-
placed and are not perceived) and object tracking. Re-
searchers have used the procedure of dishabituation,
which is designed to assess preferences for stimuli with-
out requiring much behavior. Infants are shown a stimu-
lus until they are used to it (habituated), and then they
are shown an altered stimulus. If they show increased at-
tention to the new stimulus (dishabituation), the conclu-
sion drawn is that they have noticed the difference.

Page 34
The Crisis of Variability and the Cartesian Synthesis in Developmental Science 345
A well-known case is Baillargeon’s research on ob-
ject permanence in young infants (Baillargeon, 1987,
1999). To appreciate the problems with focusing on
only selective aspects of variability, it is useful to place
this study in the context of Piaget’s (1954) original
findings and interpretations regarding infant object per-
manence. Piaget described a six-stage sequence in in-
fants’ construction of object permanence, which
subsequent research confirmed with some revision and
clarification (McCall, Eichorn, & Hogarty, 1977; Uz-
giris & Hunt, 1987).
Piaget offered a constructivist interpretation of his
observations: a simple activity-based mechanism to
explain transitions from one stage to another. By coor-
dinating early sensorimotor activities on objects to
form new, more comprehensive action systems, infants
gradually construct more inclusive understandings of
what they can do with objects and therefore how ob-
jects can behave. For instance, by coordinating the
sensorimotor actions for looking at and grasping ob-
jects at Stage 2, infants of about 5 to 6 months of age
move to a new Stage 3 structure for dealing with ob-
jects—visually guided reaching, in which they simul-
taneously hold and observe an object. Piaget described
an especially important transition at stage 4, when in-
fants of about 8 months coordinate different visually
guided reaching skills into a system for searching out
objects that have been displaced or hidden. For in-
stance, infants coordinate two skills (what Piaget
called “schemes”): reaching for a rattle to grasp it, and
reaching for a cloth that is covering the rattle to re-
move it. With this stage 4 coordination, they can begin
to understand how objects come to be hidden by other
objects and why hidden objects remain available to be
retrieved. Later stages in this understanding extend to
late in the second year of life, when infants become
able to search exhaustively for hidden objects in many
possible hiding places.
In contrast to Piaget’s model of gradual construc-
tion of object permanence, Baillargeon focused on the
lower end of the age range and a simple looking task.
Infants from 3 to 5 months of age were habituated to
the sight of a small door that rotated upward from a flat
position in front of them, tracing a 180% arc away from
them to lie flat again on a solid surface. They were then
shown two scenes with objects inserted behind the ro-
tating door. In the possible event, the door swung up
but stopped at the object. In the impossible event, the
object was surreptitiously removed and the door was
seen to swing right through the space the object had
occupied, as if it moved through the object. Infants as
young as 312 to 412 months dishabituated to the impos-
sible event significantly more than they did to the pos-
sible, and Baillargeon took this behavior as evidence of
object permanence. She concluded that infants acquire
object permanence 4 to 5 months earlier than the age of
8 months that Piaget had reported.
This argument from precocity is straightforward: If
behaviors associated with a conceptlike object perma-
nence can be found much earlier than in prior research,
then the concept in question must be present innately.
Similar evidence has led to claims of innate determina-
tion for a growing list of concepts, including object
properties, space, number, and theory of mind (Carey &
Gelman, 1991; Saxe, Carey, & Kanwisher, 2004; Spelke,
2000). Based on the static Cartesian model, these
claims have important limitations centered on the fail-
ure to consider the full range of variability involved in
developmental phenomena.
The crux of the problem is a simplification that ig-
nores the gradual epigenetic construction of activities
that vary in complexity. Baillargeon’s task and proce-
dure were dramatically different from the more complex
method of assessment used by Piaget. In place of inde-
pendent problem solving in which the infant must ac-
tively search for an object hidden in several successive
places, Baillargeon substituted a simple look toward one
of two displays. This procedure simplifies the task so
greatly that it shifts from a conceptual task to one of
perceptual anticipation. Indeed, on a computer a neural-
network model of the situation can solve a similar task
with a simple visual strategy and no coordination of ob-
ject characteristics with spatial location (Mareschal,
Plunkett, & Harris, 1999).
Baillargeon and other nativists claim that the object
concept appears very early, even though the more com-
plex behaviors described by Piaget still develop at the
usual later ages, as shown by overwhelming evidence.
The selective focus on one early age for one behavior
obscures the constructive mechanisms of development
and makes it seem that the concept of object perma-
nence has suddenly leaped up, fully formed, at 312
months of age. Within this framework, innate concepts
emerge abruptly in the first few months of life, and de-
velopment disappears. How could such early develop-
ment arise except through innate concepts? The answer
to this question is another question: How do skills de-
velop through a long sequence of increasingly complex

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346 Dynamic Development of Action and Thought
object-related activities of which the looking behavior is
only the beginning?
Competence/Performance Models
Nativists and many other cognitive scientists answer by
distinguishing between competence and performance.
The modern version of the competence/performance
distinction was proposed by Chomsky (1965) in an ef-
fort to explain why his theory of innate linguistic rules
could not predict the wide range of variability observed
in actual language usage. Chomsky argued that innate
language rules existed separately from the performance
of specific acts of communication. The rules governed
which communication practices are possible but not
which ones will actually take place in a given situation.
Many developmental scientists, faced with the similar
problem of explaining why formal Piagetian conceptions
of logic do not predict observed patterns of variability in
cognitive performance, adopted this distinction (Flavell
& Wohlwill, 1969; Gelman, 1978; Klahr & Wallace,
1976; Overton & Newman, 1982).
Competence/performance theories based on the Pi-
agetian and Chomskian models portray cognitive struc-
tures as fixed rule sets in the mind/brain that specify
behaviors but are somehow impervious to or indepen-
dent of the contexts of the behaviors. The structures
exist somewhere in the background and serve a limiting
function: They determine the upper limit on the range of
actions possible at a given time, but they leave open the
specific action that will take place. For example, in
arithmetic, the counting behavior of a preschool child
arises from a mathematical competence such as being
able to directly perceive numbers of objects of 1, 2, or 3.
When a child fails to count, say, three pretzels accu-
rately, the failure is explained by some interference such
as memory failure or distraction (Freeno, Riley, & Gel-
man, 1984; Spelke, in press). A skilled person can in-
deed mess up a performance here and there because of
memory failure or distraction, but when the 3-year-old
fails almost all tasks for counting three objects, what
sense does such an explanation make?
These models dismiss variability in cognitive and lan-
guage performance by asserting that fixed competence is
differentially expressed because of intervening cognitive
processes (vaguely specified) or as a result of unanalyzed
environmental resistance to the competence, as Piaget
suggested for decalage. Although most nativist theories
assume such a framework, some competence/perfor-
mance theories do not require that psychological struc-
tures exist innately, but only that they are firmly sepa-
rated from the actions that instantiate them. The
dynamics of construction of activities leading to wide
variation are lost in the muddy mediators that somehow
prevent competence from being realized in activity. Such
conceptions of disembodied structure seem not too dis-
tant from the humorous idea of bottling up the structure
of the Golden Gate Bridge. Why is it necessary to posit
separate levels of structure, existing somewhere (it is un-
clear where) outside the real activity in question? Why
not model the organization of the actual mental and phys-
ical activity as it exists in its everyday contexts?
In short, domain specificity, nativist, and compe-
tence/performance models share the same fatal limita-
tions as the logical stage models they were meant to
replace. Although the newer models do not make the
cross-domain claims that stage models did, they retain a
conception of psychological structure as static form
existing separately from the behavior it organizes.
Whether such static forms are seen as universal logics
or domain-specific modules, they offer accounts only of
stability in the organization of behavior while ignoring
or marginalizing variability. The challenge for contem-
porary developmental science is not to explain away evi-
dence of variability in performance. Instead, scholars
need to build dynamic models of psychological struc-
ture, using concepts such as skill, hierarchical complex-
ity, contextual support, and developmental web to build
methods for analyzing and explaining both the variabil-
ity and the stability in the organization of dynamic
human activity.
The Constructivist Alternative
The constructivist alternative takes as its starting point
what the Cartesian framework rules out: the construc-
tive agency of a human being acting in the context of re-
lationships among systems—biological, psychological,
and sociocultural. As we have shown in the opening sec-
tions of this chapter, the dynamic structural framework
provides a straightforward, comprehensive alternative
to the conundrums created by the Cartesian synthesis
and the related structure-as-form paradigm. Human
knowledge is neither passively received from the envi-
ronment nor passively received from the genome. In-
stead, people construct knowledge through the active
coordination of action systems beginning with the earli-

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Methodology of Dynamic Structural Analysis 347
est sensorimotor activities of newborns, influenced by
environmental and genetic systems. By coordinating the
systems of activity (including perceptual activities)
through which they participate in the social and physical
worlds, infants create new relations among these sys-
tems and thus new potentials for acting in and under-
standing the world. These new relations among action
systems constitute psychological structures—the orga-
nizational aspect of human knowledge, which we refer
to as skills. They exhibit both wide variations and pat-
terns of order within the variations.
Dynamic systems research provides the framework
for this alternative account, drawing on traditions that
have developed outside of or as an alternative to the
Cartesian tradition. Important concepts and methods
come from epistemological constructivism and related
sociocultural/sociohistorical theory (Cole, 1992; Ro-
goff, 2003), traditional systems theory (Dixon &
Lerner, 1992; von Bertalanffy, 1976), dynamic systems
theory (Thelen & Smith, 1994, Chapter 6, this Hand-
book, this volume; van der Maas & Molenaar, 1992; van
Geert, 1991), and the developmental science group
(Cairns, Elder, & Costello, 1996; Cairns, Chapter 3;
Valsiner, Chapter 4, this Handbook, this volume). These
traditions, while differing in many ways, share a con-
structivist focus on action, interrelatedness, and com-
plexity of psychological, biological, and sociocultural
systems. From this perspective, the person is the pri-
mary agent of cognitive change, constructing new kinds
of relations among psychological systems with biologi-
cal and cultural systems (Bidell & Fischer, 1996; R.
Kitchener, 1986). These relations are organized in par-
ticular ways that give rise to specific patterns of perfor-
mance, and they are complex and variable because they
are living systems.
People construct the skills of human understanding
and action through their diverse bodies, the variable
physical world, different sociocultural relations, and
distinct developmental histories, thus producing highly
variable activities. If this variability is ignored, it
acts as noise disguising the nature of developmental
processes and thus misleading researchers and educa-
tors. However, if the tools of developmental analysis are
used to control and manipulate conditions contributing
to variability, then the systematicity of the variability
can be uncovered and it becomes a key to understanding
the nature of psychological structure. In the next sec-
tion, we discuss some of the methodological tools by
which developmental variability can be used to under-
stand and describe the development of dynamic psycho-
logical structure.
METHODOLOGY OF DYNAMIC
STRUCTURAL ANALYSIS
To overcome the limitations of structure as static form,
we need to articulate a framework for dynamic develop-
ment, which includes a set of methods that embody dy-
namic concepts. Classical research methods use static
notions, indicating the age when a competence emerges
(really, the mean or modal age for one context and one
group), forcing growth into linear models, and partition-
ing analysis of activities into dichotomies such as hered-
ity and environment or input and output (Anderson
et al., 2004; Horn & Hofer, 1992; Plomin et al., 1997;
Wahlsten, 1990). Most importantly, effective research
needs to be designed so that it can detect variability and,
in turn, use the variability to uncover sources of order or
regularity in development.
Effective research should be built with designs, mea-
sures, analytic methods, and models that can detect
variations in growth patterns. Research must be de-
signed to deal with variability, or it is doomed to fail to
provide an adequate analysis of development. This chap-
ter focuses on activities in which people coordinate and
differentiate lower-order components to form higher-
order control systems, which encompasses most activi-
ties of interest to developmental and educational
researchers. The components of these control systems
range from neural networks to parts of the body, imme-
diate contexts (including objects and other people), and
sociocultural frameworks for action. Moment by mo-
ment, people construct and modify control systems, and
the context and goal of the moment have dramatic ef-
fects on the nature and complexity of the systems. Fre-
quently, people do the construction jointly with others.
To go beyond static stereotyping of development and
learning, research must deal directly with these facts of
variation. Research must be designed to deal with the
wide range of shapes of development that occur for dif-
ferent characteristics of action and thought in diverse
contexts and conditions.
Developmental regularities can be found at several
levels of analysis, from brain activities to simple actions,
complex activities, and collaborations in dyads or larger
groups. In analyzing these developmental regularities, it

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348 Dynamic Development of Action and Thought
is important to avoid a common mistake. No one regular-
ity applies to all characteristics of developing activity or
all levels of analysis. The same developmental regulari-
ties will not be found everywhere. That is an essential
principle of the variability of human activity.
In one major realization of this principle, develop-
ment has many different shapes! Some behaviors and
brain characteristics show continuous growth, others
show clusters of spurts and drops, still others show
oscillation, and some show growth followed by decay
(Fischer & Kennedy, 1997; Siegler, Chapter 11, this
Handbook, Volume 2; Tabor & Kendler, 1981; Thatcher,
1994; Thelen & Smith, Chapter 6, this Handbook, this
volume; van Geert, 1998). Ages of development likewise
vary dynamically, even for the same child measured in
the same domain: Assessment condition, task, emotional
state, and many other factors cause ages to vary dramat-
ically. There are no legitimate developmental milestones,
stones fixed in the developmental roadway in one posi-
tion. Instead, there are developmental buoys, moving
within a range of locations affected dynamically by var-
ious supports and currents.
It is remarkable how pervasively researchers ignore
or even deny variations in shape and age of development.
Scholars committed to a continuous view of development
typically ignore the spurts and drops in many develop-
mental functions, insisting that development is smooth
and continuous despite major evidence to the contrary.
Physical and psychological development are both rou-
tinely graphed with smooth curves, as in the charts in a
pediatrician’s office, even though research on individ-
ual growth consistently shows patterns of fits and starts
in virtually all aspects of physical growth (Lampl &
Johnson, 1998). The distortion is just as pervasive in
psychological development. For example, Diamond’s
(1985) findings of linear growth of memory for hidden
objects in infancy are frequently cited, even though
replications by others with the same tasks and measures
show nonlinear, S-shaped growth (Bell & Fox, 1992,
1994). Many data sets show powerfully nonlinear indi-
vidual growth as the norm in infant cognitive and emo-
tional development as well as development at later ages
(Fischer & Hogan, 1989; McCall, Eichorn, & Hogarty,
1977; Reznick & Goldfield, 1992; Ruhland & van
Geert, 1998; Shultz, 2003).
In a similar manner, at the other pole of argument,
scholars committed to stage theory often ignore the evi-
dence for continuous growth, even in their own data.
For example, Colby, Kohlberg, Gibbs, and Lieberman
(1983) asserted that their longitudinal data on moral de-
velopment showed stages in growth even in the face of
clear evidence that growth was gradual and continuous
(Fischer, 1983). In the same way for age, scholars rou-
tinely talk as if there are developmental milestones at
specific ages, despite the massive evidence of variability
in age of development with variations in conditions of as-
sessment (Baron-Cohen, 1995; Case, 1985; Spelke, in
press). Common claims, for example, are that object per-
manence develops at 8 months in Piagetian assessments,
conservation at 7 years, and combinatorial reasoning at
12 years, although no such statement is tenable without
more specification because the ages vary greatly with
task, support, and so on. Classic research on reflexes in
very young infants even demonstrates variability in the
ages at which they emerge and disappear (Touwen, 1976).
Starting in the Middle of Things:
Implications for Design
To study development in medias res—in the middle of
things—research designs need to be broadened so that
they capture the range of variation and diversity of
human activities in real-life settings. If development is
assessed with an instrument that places all behavior on a
single linear scale, for example, then nothing but that lin-
ear change can be detected. The limitations of most clas-
sical research arise from assumptions that restrict
observation and theory to one-dimensional analysis.
When those assumptions are changed, research opens up
to encompass the full range of human activity. By limit-
ing developmental observation and explanation to one-
dimensional processes, the static assumptions have
stymied investigation of the richly textured dynamic
variations of development. To do research that facilitates
multidimensional-process explanation requires building
research designs that go beyond one-dimensional as-
sumptions to provide for detection of the dynamics of
variability (Edelstein & Case, 1993; G. Gottlieb,
Wahlsten, & Lickliter, Chapter 5, this Handbook, this
volume; Lerner, 2002; Thelen & Smith, 1994, Chapter 6;
Valsiner, Chapter 4, this Handbook, this volume; van
Geert & van Dijk, 2002).
Here are four important one-dimensional assump-
tions that are typically incorrect and that are embodied
in research designs that implicitly assume static struc-
ture. These all need to be avoided in designs for assess-
ing the dynamics of change by addressing variability
and diversity.

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Methodology of Dynamic Structural Analysis 349
1. Single-level, single-competence assumption—not. At
any one moment, a person functions at a single
cognitive stage or a single level of complexity and
possesses a single competence. Contrary to this one-
level, one-pathway assumption, people function at
multiple developmental levels concurrently, even
within the same situation (Fischer & Ayoub, 1994;
Goldin-Meadow & Alibali, 2002; Siegler, Chapter
11, this Handbook, Volume 2). In development, a per-
son moves through a web of connected pathways
composed of multiple strands (domains or tasks),
each involving variation within a range or zone of de-
velopmental levels, as illustrated in the webs in Fig-
ures 7.2 and 7.9. Assessments must include multiple
pathways and multiple conditions so that the full
range of levels and competences can be detected.
2. Single-shape assumption—not. Each developmental
pathway shows essentially similar linear or monoto-
nic shapes. Contrary to this linearity assumption,
developmental pathways or strands take many dif-
ferent shapes, which frequently include reversals in
direction—not only increases but also decreases, as
illustrated in Figure 7.11. Individual people nor-
mally grow in fits and starts both physically and
psychologically, as we described in the introduction
to this section. In development, these fits and starts
seem to be especially prevalent and systematic
when people are functioning at optimum or when
they are building a new skill in microdevelopment.
Developmental pathways or strands for individual
activities move through nonlinear dynamic patterns
of change, seldom showing straight lines. In long-
term development, there are periodic movements to
a lower level (regressions), especially after develop-
mental spurts (Fischer & Kennedy, 1997). In mi-
crodevelopment, backward movement to a low-level
skill is common before construction of a new skill
(Granott & Parziale, 2002), as we discuss in the
section on Microdevelopment.
3. Single-person assumption—not. People develop and
learn individually, and they sometimes interact and
affect each other. Contrary to this individualist as-
sumption, people do not usually function solo, but in-
stead from birth they act in a fundamentally social
way, working together in ensembles that distribute a
task across several collaborating partners (Bronfen-
brenner & Morris, Chapter 14, this Handbook, this
volume; A. Brown & Palincsar, 1989; Scardamalia &
Bereiter, 1999; Vygotsky, 1978). Studying develop-
ment socially is not only more realistic, but it can also
make the processes of development more transparent.
When people work together, communicating about
what they are doing, the internal processes of learn-
ing and thinking become externalized, and the
processes of social collaboration and interference be-
come evident (Fischer & Granott, 1995).
4. Single context assumption—not. The most effective
research typically focuses on one task and variations
on it or one context for assessment. Contrary to this
uniformity assumption, research needs to combine
multiple tasks and assessment contexts so that it can
capture the range of levels and competences, path-
ways, and social interactions that characterize devel-
opment (Bronfenbrenner, 1993; Campbell & Stanley,
1963; Fischer, Knight, et al., 1993). To accurately de-
scribe people’s developing activities, research must
be designed with an array of assessment conditions
and an array of tasks within conditions.
Guidelines for Developmental Research
To analyze and understand natural variations in de-
velopment as well as consistencies across variations,
research needs to move beyond these limiting as-
sumptions. Analyzing the dynamics of change requires
Figure 7.11 Three different growth curves based on the
same growth model. The growth curves are all generated by
the same nonlinear hierarchical model of development of self-
in-relationships used in this chapter, but variations in the val-
ues of the parameters in the equations produce vastly different
shapes. The same growth processes produce essentially monot-
onic growth (Grower 1), growth with stagelike spurts and
drops (Grower 2), and fluctuating change (Grower 3).
800
700
600
500
400
300
200
100
0
1
2
3
4
5
6
7
8
Events or Age
Level
0
2
1
3

Page 39
350 Dynamic Development of Action and Thought
methods that allow detection of variations in develop-
ment and learning:
• People develop along multiple concurrent path-
ways in a web.
• From moment to moment people function across a
range of different levels and competences.
• People develop in the long run and learn in short time
periods according to diverse shapes of growth, in-
cluding the complex nonlinear fits and starts in many
growth curves.
• People learn and develop in social ensembles, and re-
search should reflect this fundamentally social na-
ture of development.
• People act differently in different tasks and condi-
tions, and so research needs to include a range of
tasks and conditions to detect the full range of vari-
ability in action and thought.
Only through analyzing the natural variability in devel-
opment and learning can researchers come to understand
the consistencies inside the variation.
Putting together all these contributions to variation
can seem daunting, but it need not be. A few straight-
forward guidelines in designing research and analyzing
observations facilitate uncovering the variation and di-
versity of development. Investigators should focus on
(a) using well-designed clocks and rulers to measure
change and variation, (b) studying several tasks and do-
mains to determine the generality and variation in
pathways, (c) varying assessment conditions to uncover
the range of variability in level and content, and (d) in-
vestigating diverse sociocultural contexts to discover
the effects of different cultural groups on development.
No one study can investigate all sources of variation at
once, but investigators can make sure that several
sources are evaluated in each study. Also researchers
need to situate their findings within a conceptual map
of the multiple sources of dynamic development, avoid-
ing the pitfall of reductionist description, which as-
sumes that one study captures the important sources
of variation.
Clocks, Rulers, and Repeated Measures
Detection of variation in developmental shapes requires
both good clocks and good rulers to measure change. To
capture either smooth growth or fits and starts requires
a clock that can detect the speed of change. Ages or
events need to be sampled frequently enough to provide
several assessments for each period of increase and
decrease. Otherwise, the shape of growth cannot be de-
tected. Also, the distribution of ages or times of assess-
ment must be chosen carefully so that estimates of
changes in item or response distributions are not dis-
torted by biases in time sampling. Much developmental
research uses clustered ages such as groups of 2- and 4-
year-olds clustered tightly around the mean ages of 2
and 4. This design assumes the importance of mean dif-
ferences and provides a bad clock for development, be-
cause it represents only a few of the many points along
the time scale from 2 to 4 years. If major reorganiza-
tions of activity are hypothesized to occur, for example,
every 6 months in the early preschool years as Case
(1985) predicted, then assessments must take place at
least every 2 or 3 months to reliably detect the periods
of reorganization, and the distribution of ages across 2-
or 3-month intervals should be uniform, not clustered at
the mean age.
Capturing the shapes of development requires a good
ruler as well, one that provides a scale sensitive enough
to detect the ups and downs of growth. The best assess-
ments provide a relatively continuous developmental
scale of increasing complexity, such as the Uzgiris-Hunt
(1987) scales to assess infant development and the
scales for nice and mean social interaction (Ayoub &
Fischer, in press; Fischer, Hencke, & Hand, 1994). It is
crucial to avoid scales that combine items in a way that
forces growth into a particular function, as when intelli-
gence tests force test data into scales that show linear
increase with age.
A single task seldom makes a good ruler because it
provides such a limited sample of behavior. Better is a
series of tasks or a grouping of tasks that forms coher-
ent developmental scales. A series of tasks can be used
to assess either (a) a Guttman-type developmental scale
measuring one linear pathway in a developmental web
(Guttman, 1944), like the Uzgiris-Hunt scales, or (b)
branching pathways like the tasks for nice and mean in-
teractions and those for reading single words in Figures
7.5 and 7.10. Through analysis of profiles across tasks,
a good ruler can be created for either pathway. A partic-
ularly useful method is Rasch scaling, which is based
on a sensible, nonlinear (logistic) developmental model
and allows detection of Guttman scales as well as
branches (Bond & Fox, 2001; Dawson, 2003; Rasch,
1980). The discovery of the general ruler for hierarchi-
cal skill development came from research assessing per-
formance profiles with these and related methods, as

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Methodology of Dynamic Structural Analysis 351
TABLE 7.2 Task Profiles for Normative Developmental Sequence for Reading Words
Word
Letter
Rhyme
Reading
Rhyme
Reading
Step
Definition
Identification
Recognition
Recognition
Production
Production
0
1
+
2a
+
+
2b
+
+
3
+
+
+
4
+
+
+
+
5
+
+
+
+
+
6
+
+
+
+
+
+
Note: Pass = +; Fail = −.
Adapted from “Learning to Read Words: Individual Differences in Developmental Sequences,” by
C. C. Knight and K. W. Fischer, 1992, Journal of Applied Developmental Psychology, 13, pp. 377–404.
discussed in the section titled A Common Ruler for
Skill Development.
Table 7.2 shows a set of profiles for defining the sim-
plest developmental pathway in the development of read-
ing words—Figure 7.10 (a), the pathway for normal
readers, which includes only one simple branch (Knight
& Fischer, 1992). The sequence is determined by the or-
dering patterns for every pair of tasks. For most profiles
in this simple sequence, every task is passed up to a cer-
tain point in the table from left to right, and then all tasks
are failed thereafter, which is characteristic of a Guttman
scale. Branching is indicated by profiles that show varia-
tions in this simple pattern, such as Step 2b in Table 7.2,
where there is a failed task in the middle of a string of
passes. Based on analysis of performance across tasks for
each word, a child is assigned a profile in Table 7.2, and
therefore a step in the pathway, even when assessment is
at a single time rather than longitudinal. The table shows
pass/fail tasks for simplicity, but multistep scales can be
used, with scaling tested by tasks earlier in a sequence
having higher scores than those later.
Profile analysis can detect webs as simple as the one
for normal readers in Figure 7.10 (a), or as complex as
the one for nice and mean social interactions in Figure
7.5. The logic of analysis is the same for branched webs
as for linear Guttman scales, and sequencing is deter-
mined by the ordering patterns of all pairs of tasks. In-
deed, the same set of tasks can define different webs for
different children. For example, different sets of profiles
for the tasks in Table 7.2 define the unintegrated webs
for poor readers in Figure 7.10 (b) and (c), such as the
web in which the three domains of identifying letters,
reading words, and rhyming words are all independent.
An important characteristic to keep in mind when de-
vising tasks to build rulers for change is the similarities
and differences among tasks. Simple ordering like that
in Table 7.2 is typically eliminated by differences in
content or procedure between tasks. When researchers
have attempted to build scales using distinctive tasks to
assess different steps, the task differences have wiped
out scaling of steps (Kofsky, 1966; Wohlwill & Lowe,
1962). A good, simple Guttman-type ruler uses tasks
that include only variations in complexity or difficulty,
with minimal differences in content and procedure. Dif-
ferences between distinctive tasks are captured by hav-
ing separate Guttman rulers for each set of tasks (each
domain). In a similar way, measuring the temperature of
a refrigerator in New York requires a different ther-
mometer from measuring the temperature of the surface
of Mars. Rasch analysis can also facilitate using a com-
mon scale across tasks and domains (Bond & Fox, 2001;
Dawson et al., 2003), as it has helped test the generality
of the ruler for skill complexity, showing simultaneously
the same scale across domains and large domain effects.
Another method for devising a ruler uses groupings of
similar tasks to assess a scale. For example, in early lan-
guage development, Ruhland and van Geert (1998)
grouped words into syntactical classes based on Dutch
children’s spontaneous speech to form a sensitive devel-
opmental scale. With pronouns, for example, they found
a large growth spurt late in the second year, as shown in
Figure 7.12. Other groupings that have proved useful in
studies of development have included arithmetic prob-
lems of similar complexity (Fischer, Pipp, & Bullock,
1984) and explications of dilemmas about the bases of
knowledge called reflective judgment (K. Kitchener
et al., 1993). Scales based on such groupings of similar
tasks can be used to specify the shapes of development
in various domains and to compare relations among de-
velopment across domains or levels in individual sub-
jects or groups. Like scalogram analysis, they also
provide a way of testing developmental functions with

Page 41
352 Dynamic Development of Action and Thought
Figure 7.12 Development of pronoun use in the Dutch boy
Tomas. Source: From “Jumping into Syntax: Transitions in
the Development of Closed Class Words,” by R. Ruhland and
P. van Geert, 1998, British Journal of Developmental Psychol-
ogy, 16(Pt. 1), pp. 65–95.
160
140
120
100
80
0
20
40
60
80
100
120
Age in Weeks
Number of Pronouns/Session
cross-sectional designs. For example, this method can
test for both spurts and bimodal distributions on emer-
gence of developmental levels or growth of separate
strategies for approaching a task (Siegler, 2002). The de-
sign must included separate groups of tasks for each
level or strategy. The grouping method, however, does
not provide a sensitive index of the intervals in a scale
between points of discontinuity, or levels.
Rasch analysis fills this need, providing powerful
tools for assessing the steps and intervals along a scale
as well as discontinuities (Bond & Fox, 2001; Rasch,
1980). Only recently have researchers begun to realize
its potential for assessing developmental scales and de-
termining the distances between items along a scale.
Most investigators have used it to determine whether
items in a domain fit a single Guttman scale and what
the distances are between items along that scale, and it
can also be used to assess for several independent scales
or branches in a web. Rasch scaling provides one of the
most convincing sources of evidence for the scale for
hierarchical complexity of skills shown in Figure 7.3
(Dawson, 2003; Dawson et al., 2003).
The three techniques for combining tasks to form
developmental scales (Guttman scaling, groupings of
similar tasks, and Rasch analysis) provide a repeated-
measures assessment that has many of the desirable
characteristics of longitudinal assessment, even when
there is only a single session. Through analysis of task
profiles and distributions, each person can be tested to
determine whether he or she follows a particular devel-
opmental pathway or growth function. Contrary to
the conventional wisdom that development can only
be effectively assessed longitudinally over months
and years, these repeated-measures assessments can
provide powerful tools for describing and testing devel-
opmental pathways and growth functions. They can
also be combined with longitudinal designs, where
they provide even more powerful tools for assessing
development.
General Structure across Tasks in a Domain
Task differences are typically controlled for and
systematically manipulated in developmental scales.
However, task differences are important in their own
right. Task is one of the most powerful sources of vari-
ability in behavior, as documented by thousands of
psychometric and experimental studies across many
decades (Fleishman, 1975; Mischel, 1968). An accurate
portrait of development requires assessment of different
tasks and domains to capture patterns of variation in de-
velopmental pathways and growth functions.
One of the most common hypotheses in cognitive and
developmental science is that behavior divides into do-
mains, which are built on general psychological
structures. That is the core of the domain specificity
framework and of neo-nativist explanations. However,
evidence for generality in a conceptual structure is rela-
tively rare in the research literature, where careful tests
of generalization are infrequent (Fischer & Immordino-
Yang, 2002). Many abilities that have been described as
general competences seem not to be coherent abilities at
all but instead summary variables, with at best weak cor-
relations among items. Examples include the hypothe-
sized domains of theory of mind, metamemory, visual
thinking, and ego resiliency, for each of which there is
no clear evidence of a central generalized structure that
generates common activity across a wide array of tasks.
For example, ego resiliency has been posited as a broad
characteristic of effective people and it has been sub-
jected to extensive longitudinal study by Jack and Jeanne
Block (Block, 1993). Research on this general compe-
tence in Dutch and American children indicates that ego
resiliency does not affect relevant specific competences
such as school achievement and social preference (Har-
ter, 1999; van Aken, 1992). That is, it does not show a
generalizing relation with specific skills, which would
indicate a common structure applied across tasks. Ego
resiliency may be a useful social construct, but it does
not seem to be a central psychological structure that or-
ganizes various activities together in development.

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Methodology of Dynamic Structural Analysis 353
One convincing case of a general structure in a do-
main is the central conceptual structure documented by
Robbie Case and his colleagues (1996). It provides a
model for defining a general structure and testing its
generality. Assessment of the development of a general
concept of number requires an array of tasks that all re-
quire the use of that concept. Case and his colleagues
have constructed such a task array for the elementary
number line, which represents number as quantitative
variation along a line. This representation constitutes
what they call a central conceptual structure for number
in young children, a framework for thinking about num-
ber that facilitates numerical understanding across many
situations. Tasks like reading the time on a clock, count-
ing gifts at a birthday party, and doing simple arithmetic
problems in school all make use of this same structure.
Discovery of general conceptual structures like the
number line would be a strong boon for educators,
greatly streamlining their efforts to teach children the
basic concepts and skills required by modern society.
From approximately 4 to 8 years of age, children
build the central conceptual structure for number.
When instructors and curriculum explicitly teach the
structure, children evidence a major improvement in
performance across a wide array of number tasks but
not for tasks in other domains such as understanding so-
cial interactions. The change amounts to as much as
50% of the variance in test scores, which is a remark-
ably large effect. The use of many tasks allowed Case
and his colleagues to determine how general the struc-
ture is—where children apply it and where they do not.
Note also that along with the general change across
number tasks, the researchers still found large task ef-
fects and considerable developmental variation in level.
The generality of the structure operates within this
substantial variability.
In the behavioral sciences, researchers commonly
wish to generalize from their data to the development
of a domain, but the two standard methods preclude le-
gitimate generalization by artificially reducing varia-
tion instead of analyzing it. First, in the “psychometric
method,” commonly used in intelligence, education, and
personality testing, many tasks are summed and only
the summary scores are considered. A boy’s IQ score is
116, or the college entrance test score for a young
woman is 575. Most of the variation in each person’s
performances on the tasks is ignored. Second, in the
“experimental method,” commonly used in experimental
psychology and neuroscience, a researcher analyzes one
task by varying a parameter and calculating mean per-
formance differences for specific values of the parame-
ter. Variations in performance in the task other than the
means are treated as error variance and not analyzed
further. Also, variations among diverse tasks are ig-
nored because only one task is examined.
The psychometric strategy is evident in ability theo-
ries, where researchers study some hypothesized gen-
eral ability such as spatial intelligence or verbal
intelligence (Demetriou et al., 2002; Sternberg, Lautrey,
& Lubart, 2003). The evidence for the coherence of
these supposedly modular abilities is modest in compar-
ison to Case’s evidence for a central conceptual struc-
ture for number. Most tasks or items that measure each
ability or intelligence have only minimal variance in
common, with correlations between pairs of items typi-
cally accounting for approximately 4% of the variance
(an average correlation of .2 between individual items).
Educational researchers have regularly thrown up
their hands in dismay that they have found so little gen-
eralization or transfer of concepts to tasks that are dis-
tinct from those taught (Salomon & Perkins, 1989). For
example, when instructors teach a concept such as grav-
ity, evolution, or working memory, they commonly find
that even intelligent students have difficulty using the
concept in tasks different from those explicitly taught
in class. The reason for the difficulty of this far gener-
alization (use of knowledge in tasks far from the origi-
nal object of learning) is that the construction of
generalized skills requires time and effort (Fischer &
Immordino-Yang, 2002). Furthermore, even with a
strong conceptual structure like Case’s number line,
generalization is not perfect. For a weak structure such
as spatial intelligence or eg