About this item:

495 Views | 0 Downloads

Author Notes:

To whom correspondence may be addressed: E-mail: jpokorn@emory.edu or dewaal@emory.edu

Contributed by Frans B. M. de Waal, October 22, 2009

Author contributions: J.J.P. and F.B.M.d.W. designed research; J.J.P. performed research; J.J.P. and F.B.M.d.W. analyzed data; and J.J.P. and F.B.M.d.W. wrote the paper.

We thank Christine Webb, Kristin Leimgruber, Amanda Greenberg, Eva Kennedy, Charine Tabbah, Daniel Brubaker, Karianne Chung, and Tara McKenney for technical assistance; William Hopkins, Robert Hampton, Philippe Rochat, and Kim Wallen for helpful discussions; and the animal care and veterinary staff at the Yerkes National Primate Research Center (YNPRC) for the maintenance and care of our research subjects.

The YNPRC is fully accredited by the American Association for Accreditation for Laboratory Animal Care.


Research Funding:

Research was supported by Grant IOS-0718010 from the National Science Foundation (to F.B.M.d.W.) and by a base grant (RR-00165) from the National Institutes of Health to YNPRC.


  • face recognition
  • individual discrimination
  • oddity
  • primate
  • visual discrimination

Monkeys recognize the faces of group mates in photographs


Journal Title:

Proceedings of the National Academy of Sciences


Volume 106, Number 51


, Pages 21539-21543

Type of Work:

Article | Post-print: After Peer Review


Nonhuman primates posses a highly developed capacity for face recognition, which resembles the human capacity both cognitively and neurologically. Face recognition is typically tested by having subjects compare facial images, whereas there has been virtually no attention to how they connect these images to reality. Can nonhuman primates recognize familiar individuals in photographs? Such facial identification was examined in brown or tufted capuchin monkeys (Cebus apella), a New World primate, by letting subjects categorize facial images of conspecifics as either belonging to the in-group or out-group. After training on an oddity task with four images on a touch screen, subjects correctly identified one in-group member as odd among three out-group members, and vice versa. They generalized this knowledge to both new images of the same individuals and images of juveniles never presented before, thus suggesting facial identification based on real-life experience with the depicted individuals. This ability was unexplained by potential color cues because the same results were obtained with grayscale images. These tests demonstrate that capuchin monkeys, like humans, recognize whom they see in a picture.

Copyright information:

© 2014 National Academy of Sciences

Export to EndNote