Do Geladas Console Their Victims? Testing the Anxiety Reduction Hypothesis

Triadic affiliation is defined as the first post-conflict affiliative contact directed by third parties to one of the two opponents. It can be spontaneously offered by the bystander to the victim or can be provided on request of the victim (solicited affiliation). Such affinitive contacts have a consolatory function if they are spontaneously directed towards friends or kin and reduce anxiety (measured via scratching) in the victim. Up to now, within the order Primates, consolation has been demonstrated in only humans, chimpanzees, bonobos and Tonkean macaques. Here, we tested specific hypotheses on the potential functions of triadic affiliation in geladas (Theropithecus gelada), a species living in complex multi-level societies. Geladas engaged in spontaneous triadic affiliation towards the victim, but we failed to find any evidence for the presence of solicited triadic affiliation in our study group. Playing, touching and lip-smacking/vocalization were the most frequent affiliative patterns directed by bystanders towards the victims. Third-party affiliation also occurred more frequently in the absence of reconciliation, defined as the first affinitive contact between the former opponents immediately after a fight. Even though spontaneous triadic affiliation was not mainly directed towards kin or friends, it significantly improved the emotional state of the victims by lowering their levels of anxiety, especially when the conflict was not resolved through reconciliation. It remains to be understood if the improvement of the affective state of the victim is linked to the physical closeness and protection provided by the bystander; a situation that lowers the probability for the victim to be re-attacked by the former opponent. The improvement of the emotional state of the victim could also be due to the activation of a victim-bystander emotional attunement, which translates into the activation of the prosocial behaviour named consolation.