What to do after a fight? The determinants and inter-dependency of post-conflict interactions in chimpanzees

Abstract

Primates resolve conflicts through post-conflict interactions (PCI). However, the occurrence of different PCI in relation to one another is not well understood. Furthermore, the factors influencing the occurrence of PCI are rarely addressed together, and thereby their relative impact is usually ignored. We investigated the occurrence and interrelatedness of five PCI, namely reconciliation, further (or redirected) aggression, third-party affiliation, third-party aggression and 'no PCI' in captive chimpanzees. Most PCI were found to occur independently from each other. Reconciliation was determined by relationship attributes between the opponents. Further aggression was mainly determined by directionality and intensity of conflicts. Opponents received third-party affiliation most often when they were likely to redirect aggression to third parties, although in aggressees this aspect was less clear than in aggressors. The predictors for third-party aggression and 'no PCI' remained unclear or insignificant. Overall, the results indicate that (1) most PCI do not directly depend on one another and that (2) the conflict opponents and the bystanders each make their own 'decisions' about which PCI to employ depending on specific conflict characteristics, the conflict outcome and the relationship attributes among the opponents. This study emphasises the multidimensionality of primate conflict resolution.