Graduation Year


Document Type




Degree Granting Department


Major Professor

Sarah Partan, Ph.D.

Co-Major Professor

Judith Bryant, Ph.D.

Committee Member

Jon Rottenberg, Ph.D.

Committee Member

Ann Weaver, Ph.D.


aggression, agonism, communication conflict resolution, primate


This study aimed to examine whether mandrills (Mandrillus sphinx) reconcile their conflicts. The data were collected from a captive group of nine mandrills (5 males and 4 females) at the Lowry Park Zoo that ranged in age from 3 to 16 years at the time of study. After a conflict was observed, the behavior of one of the two former opponents was documented for a period of ten minutes using continuous recording methods. On the next possible observation day, at the same time of the previous conflict, the behavior of the same individual was recorded for an additional ten minutes. Former opponents exchanged peaceful or affiliative signals sooner after a conflict than during control periods. These post-conflict signals were selectively directed towards former opponents, and were most likely to be exchanged in the first two minutes after a conflict's termination. The silent bared-teeth face comprised 62.5% of the first peaceful interactions between former opponents. The best predictor of the likelihood of reconciliation was the dyad's baseline rate of silent bared-teeth face exchange. Mandrill dyads with higher rates of silent bared-teeth face exchange at baseline had higher conflict rates and spent less time in non-aggressive proximity than those with lower rates of silent bared-teeth face exchange. These results are consistent with the Insecure Relationship Hypothesis, which posits that individuals with insecure relationships are more likely to reconcile because their relationships are more likely to be damaged by a conflict than those with secure relationships. The exchange of peaceful post-conflict signals did not appear to have an effect on the behavior of the former opponents.