How primates acquire their gestures: evaluating current theories and evidence.

Mechanisms underlying gesture acquisition in primates are largely unstudied, yet heavily debated. While some studies suggest that gestural repertoires are largely innate, others emphasize that gestures emerge and are shaped in social interactions with other conspecifics. There is agreement, however, regarding the negligible role of imitation for the acquisition of gestures. The aim of this paper is to provide an overview of the current knowledge about gesture acquisition in nonhuman primates, to introduce the corresponding mechanisms suggested to be involved, and to discuss how findings from current studies support the different theories of gesture acquisition. We suggest that seemingly inconsistent findings across different research groups can be reconciled by pointing to differences between their research foci as well as methods of data collection. The additional comparison of the developmental pathways of gestural and facial communication highlights the complex interplay of genetic as well as social factors involved in shaping a species repertoire. We close by proposing that extending longitudinal studies, which capture the onset and usage of gestures in young primates, and which include the comparisons of several species and groups in different environments, will enable us to better understand developmental pathways of gestural communication in primates.