Exploratory study on dyadic interactions with and without objects in western humans and chimpanzees

Abstract

The aim of this study is to analyse the development of communication and cooperation in three different kinds of dyads: a western human dyad, a chimpanzee dyad, and a dyad composed of a human and a baby chimpanzee. These three different kinds of dyads participated in this research. We observed them for 12.37 h, 9 h, and 10.6 h, respectively, using narrative register and/or video tape recordings. The results show the different roles that objects play in their interaction. In the first case, the objects were used but did not catch the partners’ attention; in the second, the baby chimp asked the person who had engaged with her previously in interactive formats, for an object. In the last case, the objects were not only asked for but also made the centre of communicative acts, for which this communication had the only aim. However, the communicative repertoires of the baby chimpanzees that were analysed did not include protodeclaratives, and their expressions were dependent on contexts. The other characteristics of their social and communicative development are discussed.