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Can chimpanzees (Pan troglodytes) discriminate appearance from reality?

Publication ,  Journal Article
Krachun, C; Call, J; Tomasello, M
Published in: Cognition
September 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.

Duke Scholars

Published In

Cognition

DOI

EISSN

1873-7838

ISSN

0010-0277

Publication Date

September 2009

Volume

112

Issue

3

Start / End Page

435 / 450

Related Subject Headings

  • Visual Perception
  • Pan troglodytes
  • Male
  • Individuality
  • Humans
  • Female
  • Experimental Psychology
  • Discrimination Learning
  • Concept Formation
  • Cognition
 

Citation

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Krachun, C., Call, J., & Tomasello, M. (2009). Can chimpanzees (Pan troglodytes) discriminate appearance from reality? Cognition, 112(3), 435–450. https://doi.org/10.1016/j.cognition.2009.06.012
Krachun, Carla, Josep Call, and Michael Tomasello. “Can chimpanzees (Pan troglodytes) discriminate appearance from reality?Cognition 112, no. 3 (September 2009): 435–50. https://doi.org/10.1016/j.cognition.2009.06.012.
Krachun C, Call J, Tomasello M. Can chimpanzees (Pan troglodytes) discriminate appearance from reality? Cognition. 2009 Sep;112(3):435–50.
Krachun, Carla, et al. “Can chimpanzees (Pan troglodytes) discriminate appearance from reality?Cognition, vol. 112, no. 3, Sept. 2009, pp. 435–50. Epmc, doi:10.1016/j.cognition.2009.06.012.
Krachun C, Call J, Tomasello M. Can chimpanzees (Pan troglodytes) discriminate appearance from reality? Cognition. 2009 Sep;112(3):435–450.
Journal cover image

Published In

Cognition

DOI

EISSN

1873-7838

ISSN

0010-0277

Publication Date

September 2009

Volume

112

Issue

3

Start / End Page

435 / 450

Related Subject Headings

  • Visual Perception
  • Pan troglodytes
  • Male
  • Individuality
  • Humans
  • Female
  • Experimental Psychology
  • Discrimination Learning
  • Concept Formation
  • Cognition