Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 May;136(2):93-104.
doi: 10.1037/com0000309. Epub 2022 Mar 21.

Sensitivity to line-of-sight in tolerant versus despotic macaques (Macaca sylvanus and Macaca mulatta)

Affiliations

Sensitivity to line-of-sight in tolerant versus despotic macaques (Macaca sylvanus and Macaca mulatta)

Rosemary Bettle et al. J Comp Psychol. 2022 May.

Abstract

Complex social life is considered important to the evolution of cognition in primates. One key aspect of primate social interactions concerns the degree of competition that individuals face in their social group. To examine how social tolerance versus competition shapes social cognition, we experimentally assessed capacities for flexible gaze-following in more tolerant Barbary macaques (Macaca sylvanus) and compared to previous data from despotic rhesus macaques (Macaca mulatta). Monkeys experienced one of two possible conditions. In the barrier condition, they observed an actor look upwards into an overheard barrier, so they could not directly see the target of the actor's gaze without reorienting. In the no barrier condition, they observed an actor look upwards without a barrier blocking her line-of-sight, so they could observe the target of the actor's gaze by also looking upwards. Both species (N = 58 Barbary macaques, 64 rhesus macaques) could flexibly modulate their gaze responses to account for the demonstrator's line of sight, looking up more often when no barrier was present, and this flexible modulation declined with age in both species. However, neither species preferentially approached to look inside the barrier when their view of the target location was obscured, although rhesus macaques approached more overall. This pattern suggests that both tolerant and despotic macaques exhibit similar capacities to track other's line of sight and do not preferentially reorient their bodies to observe what an actor looks at in this situation. This contrasts with other work indicating that competitive primates are especially adept at some aspects of theory of mind. Thus, it is important to understand both the similarities and differences in the social-cognitive abilities of primates with different social styles. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

PubMed Disclaimer

Figures

Figure 1:
Figure 1:. Methods
(a) Diagram of setup. While monkeys could see the actor’s target of attention from their starting position in the no barrier condition, they had to reorient by approaching the apparatus to do so in the barrier condition depicted here. (b) Video still of a Barbary macaque looking at the demonstrator at the start of a trial. (c) Video still of a Barbary macaque looking upwards to produce a gaze-following response.
Figure 2:
Figure 2:. Gaze following responses across species.
(a) Proportion of Barbary macaques who looked upwards during the look phase, across conditions. (b) Proportion of rhesus macaques who looked upwards during the look phase, across conditions. (c) Age trends by condition, collapsing across species. Ribbons represent 95% CI.
Figure 3:
Figure 3:. Approaches across species.
Proportion of (a) Barbary macaques and (b) rhesus macaques who approached the apparatus across conditions.

Similar articles

References

    1. Almeling L, Hammerschmidt K, Sennhenn-Reulen H, Freund AM, & Fischer J (2016). Motivational shifts in aging monkeys and the origins of social selectivity. Current Biology, 26(13), 1744–1749. - PubMed
    1. Anderson JR, Montant M, & Schmitt D (1996). Rhesus monkeys fail to use gaze direction as an experimenter-given cue in an object-choice task. Behavioural Processes, 37(1), 47–55. - PubMed
    1. Anderson JR, Sallaberry P, & Barbier H (1995). Use of experimenter-given cues during object-choice tasks by capuchin monkeys. Animal Behaviour, 49(1), 201–208.
    1. Arre AM, Stumph E, & Santos LR (2021). Macaque species with varying social tolerance show no differences in understanding what other agents perceive. Animal Cognition, 1–12. - PMC - PubMed
    1. Baayen RH, & Milin P (2010). Analyzing Reaction Times. International Journal of Psychological Research, 3(2), 12–28.

Publication types

Supplementary concepts