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 an amount of fear or anxiety of those objects. For example, see the "Methods" section of Rehousing Nonreproductive Rhesus Macaques with Weanlings.
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Sackett self-selection circus Wikipedia(Text) CC BY-SA