Gestural communication in chimpanzees (Pan troglodytes): the influence of experimenter position on gesture type and hand preference.

This study examined the influence of experimenter position on hand use in gestural communication in a sample of 127 captive chimpanzees. Hand use in gestural communication was recorded while an experimenter was positioned either left, right, or directly in front of the subject. The type of gesture was also recorded as either a food beg or whole hand point. Both hand use and gesture were consistent across experimenter positions. Overall, a significant population-level right hand bias was found, particularly for food beg gestures. These results are consistent with previous findings in chimpanzees and suggest that lateralisation in gestural communication is left hemisphere dominant.