“Requests” and “offers” in orangutans and human infants*
This paper presents two pilot studies of sharing situations in orangutans and human infants. We report on the communicative behaviors that elicit food transfers, the contingencies associated with gesture selection and the (relative) success in obtaining food. We focus on the sequential unfolding of these interactional projects, on the timing between an initial action and the responsive move, and on the semiotic features that allow a participant to recognize (a) when a request has been produced, (b) when it has been unsuccessful and, (c) in the absence of success, when to pursue it further. We claim that the infrastructure for sequentially organized, cooperative social interaction and the capacity to selectively produce communicative actions predates language evolution and is, at least to some degree, shared with other primates.