A new window onto animal culture

Scientific interest in the diversity of gestural signalling dates back to the figure of Charles Darwin. More than a hundred years later, there is a considerable body of work describing human gestural diversity across languages and cultures. However, the question of communicative culture in our closest living relatives, the nonhuman primates, is relatively unexplored. Here, we will stir new interest into this topic by (i) briefly summarizing the current knowledge of animal culture, and (ii) presenting the current knowledge on gesture cultures, diversity and usage in the most common model for early hominid behaviour, the chimpanzee (Pan troglodytes). We will focus particularly on well-established behaviours being customary in some and absent in other chimpanzee communities, and recently discovered social customs that have been suggested to differ in their form, and/or meaning across populations. We also introduce latest findings on chimpanzees’ gestural diversity, providing further evidence for the role social negotiation plays in gestural acquisition. We conclude that the field has been hampered by misconstruing great ape gestures as fixed action patterns, a strong research bias on the perspective of signalers, and a lack of coherent methodology to assess the meaning and context of gestures across sites. We argue for systematic cross-site comparisons by viewing communicative exchanges as negotiations, enabling a unique perspective onto the evolutionary trajectory of culture and communication.