Context-sensitive adjustment of pointing in great apes

Abstract

Great apes are able to request objects from humans by pointing. It is unclear, however, whether this is an associated response to a certain set of cues (e.g. the presence and attention of a human addressee) or a communicative signal which can be adjusted to relevant aspects of the spatial and social context. In three experiments, we tested captive great apes’ flexible use of pointing gestures. We manipulated the communicative context so that the default pointing response of apes would have indicated an undesired object, either due to 1) the spatial arrangements of the target objects, 2) the perspective of the addressee or 3) the knowledge of the addressee about the target objects’ location. The results of the three experiments indicate that great apes can successfully adjust their pointing to the spatial configuration of the referent environment such as distance and location of food. However, we found no evidence that they take the perspective or the knowledge of the addressee into account when doing so. This implies that pointing in great apes is a context-sensitive, but maybe less versatile, communicative signal compared to human pointing.