Myowa-Yamakoshi / Poster

Imitation of Intentional Manipulatory Actions in Chimpanzees (Pan troglodytes)

Masako Myowa-Yamakoshi and Tetsuro Matsuzawa
Kyoto University

     This study investigated the understanding of other's intention in chimpanzees (Pan troglodytes). The subjects were 5 adult chimpanzees. In each test, a human demonstrator and a chimpanzee sat face to face. The human demonstrated an attempt to open a container. Each container required a different operation to open it (pulling, pushing, and twisting). In addition to the container, there was a second object that was irrelevant to opening the container. We tested the following two conditions: the demonstrator 1) tried but failed to open the container, and 2) opened the container successfully, with the 'irrelevant tool' or by hand. After the demonstration, the subjects were given the set of objects and manipulated them. The results showed that the subjects tended to manipulate the containers using the demonstrated strategy, even after observing an unsuccessful manipulation. These findings suggest that chimpanzees anticipate the intentions of others by perceiving the directionality and causality of object(s) as available cues.