Participants were asked to estimate the steepness of hills, both from the bottom and at a cross-section, before and after a physically demanding run. The results displayed a trend for participants to estimate the steepness of the hill as greater after completing the run. Similar over-estimation occurred when participants were asked to estimate the steepness of hills when wearing a heavy backpack, or when the participant was elderly or otherwise less physically able. Another experiment placed participants at the top of a hill steep hill, standing on a skateboard. The perceived risk of bodily injury led the participants standing on skateboards to estimate the slope of the hill to be greater than their counterparts on secure ground. The author concludes that "what one sees in the world is influenced not only by optical and ocular-motor information, but also by one's purposes, physiological state, and emotions."
Perspectives on Psychological Science is a journal of the Association for Psychological Science (formerly the American Psychological Society). It publishes an eclectic mix of thought-provoking articles on the latest important advances in psychology.
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Author Dennis R. Proffitt is Professor of Psychology at University of Virginia. He is available for interviews and may be contacted.