Recipient Design in Communicative Pointing

A long-standing debate in the study of human communication centers on the degree to which communicators tune their communicative signals (e.g., speech, gestures) for specific addressees, as opposed to taking a neutral or egocentric perspective. This tuning, called recipient design, is known to occur under special conditions (e.g., when errors in communication need to be corrected), but several researchers have argued that it is not an intrinsic feature of human communication, because that would be computationally too demanding. In this study, we contribute to this debate by studying a simple communicative behavior, communicative pointing, under conditions of successful (error-free) communication. Using an information-theoretic measure, called legibility, we present evidence of recipient design in communicative pointing. The legibility effect is present early in the movement, suggesting that it is an intrinsic part of the communicative plan. Moreover, it is reliable only from the viewpoint of the addressee, suggesting that the motor plan is tuned to the addressee. These findings suggest that recipient design is an intrinsic feature of human communication.