Abstract # 101:

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


WITNESSING RECONCILIATION REDUCES AROUSAL IN BABOONS (PAPIO HAMADRYAS HAMADRYAS)

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