The Sackett self-selection circus is an apparatus used in experimental psychology with non-human primates. It is a space divided into compartments containing objects; the time an animal spends with each object is measured, indicating any amount of fear of or anxiety from those objects.Richard, David C. S. and Lauterbach, Dean L. (2006). In Handbook of Exposure Therapies. Academic Press. pp. 35-36. . Google Book Search. Retrieved on December 17, 2007.
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