Vocal signals often play an important role in synchronizing the activities of group members, coordinating decisions about when and where to travel, and facilitating social interactions in which there are potential conflicts of interest. In chacma baboons, Papio ursinus, low amplitude grunts facilitate nonaggressive social interactions and reconcile conflicts. Grunts seem to function as signals of benign intent and reduce uncertainty about the signaler's subsequent behavior. Here, we replicate and extend these findings in another...