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Proc Natl Acad Sci U S A. 2016 Sep 6;113(36):10215-20. doi: 10.1073/pnas.1611826113. Epub 2016 Aug 22.

How chimpanzees cooperate in a competitive world.

Author information

1
Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322; Department of Psychology, Emory University, Atlanta, GA 30322; Department of Animal Behavior, Ecology, and Conservation, Canisius College, Buffalo, NY 14208; suchakm@canisius.edu dewaal@emory.edu.
2
Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322; Department of Anthropology, University of Texas at Austin, Austin, TX 78712;
3
Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322; Department of Psychology, California State University-Channel Islands, Camarillo, CA 93012.
4
Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322;
5
Department of Animal Behavior, Ecology, and Conservation, Canisius College, Buffalo, NY 14208;
6
Living Links, Yerkes National Primate Research Center, Atlanta, GA 30322; Department of Psychology, Emory University, Atlanta, GA 30322; suchakm@canisius.edu dewaal@emory.edu.

Abstract

Our species is routinely depicted as unique in its ability to achieve cooperation, whereas our closest relative, the chimpanzee (Pan troglodytes), is often characterized as overly competitive. Human cooperation is assisted by the cost attached to competitive tendencies through enforcement mechanisms, such as punishment and partner choice. To examine if chimpanzees possess the same ability to mitigate competition, we set up a cooperative task in the presence of the entire group of 11 adults, which required two or three individuals to pull jointly to receive rewards. This open-group set-up provided ample opportunity for competition (e.g., freeloading, displacements) and aggression. Despite this unique set-up and initial competitiveness, cooperation prevailed in the end, being at least five times as common as competition. The chimpanzees performed 3,565 cooperative acts while using a variety of enforcement mechanisms to overcome competition and freeloading, as measured by (attempted) thefts of rewards. These mechanisms included direct protest by the target, third-party punishment in which dominant individuals intervened against freeloaders, and partner choice. There was a marked difference between freeloading and displacement; freeloading tended to elicit withdrawal and third-party interventions, whereas displacements were met with a higher rate of direct retaliation. Humans have shown similar responses in controlled experiments, suggesting shared mechanisms across the primates to mitigate competition for the sake of cooperation.

KEYWORDS:

Pan troglodytes; enforcement; freeloading; partner choice; punishment

PMID:
27551075
PMCID:
PMC5018789
DOI:
10.1073/pnas.1611826113
[Indexed for MEDLINE]
Free PMC Article

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