Intentional gestures predict complex sociality in wild chimpanzee

A key challenge for primates is coordinating behavior with conspecifics in large, complex social groups. Gestures play a key role in this process and chimpanzees show considerable flexibility communicating through single gestures, sequences of gestures interspersed with periods of response waiting (persistence) and rapid sequences where gestures are made in quick succession, too rapid for the response waiting to have occurred. Previous studies examined behavioral reactions to single gestures and sequences, but whether this complexity is associated with more complex sociality at the level of the dyad partner and the group as a whole is not well understood. We used social network analysis to examine how the production of single gestures and sequences of gestures was related to the duration of time spent in proximity and individual differences in proximity in wild East African chimpanzees (Pan troglodytes schweinfurthii). Pairs of chimpanzees that spent a longer duration of time in proximity had higher rates of persistence, but not a higher rate of single gesture or rapid sequences. Central individuals in the social network received higher rates of persistence, but not rapid sequence or single gesture. Intentional gestural communication plays an important role in regulating social interactions in complex primate societies.