WHAT CHIMPANZEES (PAN-TROGLODYTES) LEARN IN A COOPERATIVE TASK

To examine the development of cooperation in a captive group of chimpa nzees (Pan troglodytes), we designed an apparatus which required the s imultaneous traction by two animals to get a reward. Two chimpanzees, an adult male and an infant female in a group of six, produced most of the successful responses (pulling on two handles simultaneously). Vis ual behavior was used to try to determine what chimpanzees learned abo ut the cooperative task. Propositions were made to investigate what ki nd of learning could be attributed to chimpanzees and were confronted with results. Both subjects learned the link between the presence of f ruits on the apparatus and the possibility of getting a fruit. They al so learned the importance of the partner at the apparatus to make a su ccessful response. Only the adult male learned to take into account th e behavior of the partner at the apparatus before pulling a handle. Fr om a methodological point of view, the glances made by the animals can constitute a useful behavioral indicator of what the subjects learned in a given social situation.