Affect is central to conscious experience and behavior in any environment, whether natural or built, crowded or unpopulated. Because virtually no meaningful thoughts, actions, or environmental encounters occur without affect (Ittelson, 1973, p. 16; Izard, 1977; Zajonc, 1980), an affective state is an important indicator of the nature and significance of a person’s ongoing interaction with an environment (Lazarus, Kanner, & Folkman, 1980, p. 190). Research concerning affective and aesthetic response, therefore, may have a central role in advancing our understanding of human interactions with the natural environment and could prove pivotal in the development of comprehensive theories. Further, this area of research relates to important questions in environmental planning and design, including, for instance, visual landscape assessment, the provision of vegetation and parks in cities, and issues of wilderness management and recreation. Concerning the latter, it appears that aesthetic and emotional experiences are the most important benefits realized by many recreationists in the natural environment (Rossman & Ulehla, 1977; Shafer & Mietz, 1969).