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Proc Biol Sci. Dec 7, 2004; 271(Suppl 6): S468–S470.
PMCID: PMC1810104
Contagious yawning in chimpanzees.
James R Anderson, Masako Myowa-Yamakoshi, and Tetsuro Matsuzawa
Department of Psychology, University of Stirling, Stirling FK9 4LA, UK.
James R Anderson: jra1/at/
Six adult female chimpanzees were shown video scenes of chimpanzees repeatedly yawning or of chimpanzees showing open-mouth facial expressions that were not yawns. Two out of the six females showed significantly higher frequencies of yawning in response to yawn videos; no chimpanzees showed the inverse. Three infant chimpanzees that accompanied their mothers did not yawn at all. These data are highly reminiscent of the contagious yawning effects reported for humans. Contagious yawning is thought to be based on the capacity for empathy. Contagious yawning in chimpanzees provides further evidence that these apes may possess advanced self-awareness and empathic abilities.
Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of
The Royal Society