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ERIC Number: EJ850756
Record Type: Journal
Publication Date: 2009-Sep
Pages: 16
Abstractor: As Provided
Reference Count: 0
ISSN: ISSN-0010-0277
Can Chimpanzees ("Pan troglodytes") Discriminate Appearance from Reality?
Krachun, Carla; Call, Josep; Tomasello, Michael
Cognition, v112 n3 p435-450 Sep 2009
A milestone in human development is coming to recognize that how something looks is not necessarily how it is. We tested appearance-reality understanding in chimpanzees ("Pan troglodytes") with a task requiring them to choose between a small grape and a big grape. The apparent relative size of the grapes was reversed using magnifying and minimizing lenses so that the truly bigger grape appeared to be the smaller one. Our "Lens" test involved a basic component adapted from standard procedures for children, as well as several components designed to rule out alternative explanations. There were large individual differences in performance, with some chimpanzees' responses suggesting they appreciated the appearance-reality distinction. In contrast, all chimpanzees failed a "Reverse Contingency" control test, indicating that those who passed the Lens test did not do so by learning a simple reverse contingency rule. Four-year-old children given an adapted version of the Lens test failed it while 4.5-year-olds passed. Our study constitutes the first direct investigation of appearance-reality understanding in chimpanzees and the first cross-species comparison of this capacity. (Contains 7 figures and 2 tables.)
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A