Different social motives in the gestural communication of chimpanzees and human children.

Both chimpanzees and human infants use the pointing gesture with human adults, but it is not clear if they are doing so for the same social motives. In two studies, we presented chimpanzees and human 25-month-olds with the opportunity to point for a hidden tool (in the presence of a non-functional distractor). In one condition it was clear that the tool would be used to retrieve a reward for the pointing subject (so the pointing was selfish or 'for-me'), whereas in the other condition it was clear that the tool would be used to retrieve the reward for the experimenter (so the pointing was helpful or 'for-you'). The chimpanzees pointed reliably only when they themselves benefited, whereas the human children pointed reliably no matter who benefited. These results are interpreted as evidence for the especially cooperative nature of human communication.