Post-conflict affiliation by chimpanzees with aggressors: Other-oriented versus selfish political strategy

• Type of Material: Article
• Authors: Teresa Romero, University of Tokyo; Miguel A. Castellanos, Complutense University of Madrid; Frans B M De Waal, Emory University
• Language: English
• Date: 2011-07-26
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2011 Romero et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0022173
• Title of Journal or Parent Work: PLoS ONE
• ISSN: 1932-6203
• Volume: 6
• Issue: 7
• Start Page: e22173
• End Page: e22173
• Grant/Funding Information: Funding for this study has come from the National Institutes of Health's National Center for Research Resources base grant (RR-00165) to the Yerkes National Primate Research Center; the Living Links Center; and Emory College of Arts and Sciences.
• Keywords: Pan troglodytes; Behavior, Animal; Female; Databases, Factual; Animals; Aggression; Sex Factors; Male; Empathy; Conflict (Psychology)
• Research Categories: Biology, Zoology; Psychology, Behavioral

Abstract

Consolation, i.e., post-conflict affiliation directed from bystanders to recent victims of aggression, has recently acquired an important role in the debate about empathy in great apes. Although similar contacts have been also described for aggressors, i.e., appeasement, they have received far less attention and their function and underlying mechanisms remain largely unknown. An exceptionally large database of spontaneous conflict and post-conflict interactions in two outdoor-housed groups of chimpanzees lends support to the notion that affiliation toward aggressors reduces the latter's aggressive tendencies in that further aggression was less frequent after the occurrence of the affiliation. However, bystander affiliation toward aggressors occurred disproportionally between individuals that were socially close (i.e., affiliation partners) which suggest that it did not function to protect the actor itself against redirected aggression. Contrary to consolation behavior, it was provided most often by adult males and directed toward high ranking males, whereas females engaged less often in this behavior both as actors and recipients, suggesting that affiliation with aggressors is unlikely to be a reaction to the distress of others. We propose that bystander affiliation toward aggressors may function to strengthen bonds between valuable partners, probably as part of political strategies. Our findings also suggest that this post-conflict behavior may act as an alternative to reconciliation, i.e., post-conflict affiliation between opponents, in that it is more common when opponents fail to reconcile.