Abstract # 101:

Scheduled for Sunday, September 20, 2009 09:30 AM-09:40 AM: Session 9 (Del Mar Room) Oral Presentation


P. G. Judge, K. A. Bachmann and S. P. Coyne
Bucknell University, Program in Animal Behavior, Lewisburg, PA 17837, USA

Reconciliation between opponents shortly after a conflict in a primate group has been shown to reduce ongoing aggression, restore disrupted relationships, and reduce post-conflict anxiety, as indicated by reduced rates of self-directed behavior by combatants following reconciliation. The self-directed behavior of bystanders also increases after aggression, suggesting that witnessing a fight increases anxiety. We tested whether witnessing reconciliation between combatants would reduce the elevated levels of self-directed behavior occurring in bystanders. When aggression occurred in a 16-member group of captive hamadryas baboons, one observer conducted a focal sample on one of the combatants to document reconciliation (i.e., friendly contacts between opponents) and a second observer simultaneously conducted a focal sample on a randomly selected bystander [N=226 conflicts]. Matched control observations were then collected on the same individuals in a non-aggressive context to obtain baseline levels of behavior. The self-directed behavior of bystanders increased after witnessing a fight compared to baseline [Wilcoxon signed rank tests, p<0.001] and significantly decreased during the minute after combatants reconciled aggression [p<0.01]. Further, the rate of self-directed behavior by bystanders in the minute following reconciliation was significantly lower than rates during the same minute in post-conflict intervals without reconciliation [p<0.01]. Bystanders became anxious after witnessing aggression, and observing reconciliation between the combatants reduced this arousal, perhaps because animals recognized the functional significance of this conflict-reducing mechanism when it occurred in their group.