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Abstract

Animal communication has long been thought to be subject to pressures and constraints associated withsocial relationships. However, our understanding of how the nature and quality of social relationshipsrelates to the use and evolution of communication is limited by a lack of directly comparable methodsacross multiple levels of analysis. Here, we analysed observational data from 111 wild groupsbelonging to 26 non-human primate species, to test how vocal communication relates to dominancestyle (the strictness with which a dominance hierarchy is enforced, ranging from‘despotic’to‘tolerant’). At the individual-level, we found that dominant individuals who were more tolerantvocalized at a higher rate than their despotic counterparts. This indicates that tolerance within arelationship may place pressure on the dominant partner to communicate more during socialinteractions. At the species-level, however, despotic species exhibited a larger repertoire of hierarchy-related vocalizations than their tolerant counterparts. Findings suggest primate signals are used andevolve in tandem with the nature of interactions that characterize individuals’social relationships.