Abstract
Great apes deploy gestural signals in goal-directed and flexible ways across a wide range of social contexts. Despite growing evidence for profound effects of developmental experience on social cognition, socio-ecological factors shaping gesture use are still poorly understood, particularly in apes living in their natural environment. After discussing current ambiguities in terminology and methods, we review recent work implementing a longitudinal and/or cross-sectional approach in great ape gesture acquisition (phylogenetic and ontogenetic origins) and development (ontogenetic trajectories). To understand whether and to what extent the socio-ecological environment influences gestural communication, it is essential to distinguish between the gestural repertoire and gesture usage, which represent different levels of analysis. While the majority of the apes’ gestural repertoire seems to be innate, accumulating evidence shows that the communicative usage of these signals is substantially affected by interactional experiences throughout ontogeny. Nevertheless, since great ape communication is intrinsically multimodal, future developmental research on gesture should incorporate other modes of communication.