Chimpanzees know what conspecifics can and cannot see

Brian Hare

Harvard University, USA

A series of studies focusing on chimpanzee social problem solving will be presented. Utilizing a new paradigm dominant and subordinate individuals compete against each other for two pieces of food. The main result from these competitions is that subordinates retrieved more food that they alone could see opposed to food pieces that both competitors could see. Several controls were run to eliminate variables such as behavioral cueing that might have otherwise been responsible for the subordinates' preferences. From the results of this and other recent studies (Call et. al., 1998; Tomasello et. al., 1999) it is concluded that chimpanzees are sensitive to what conspecifics can and cannot see and are capable of using this knowledge to develop effective social-cognitive strategies during naturally occurring competition over food. The current paradigm will also be contrasted to previous methods employed to test similar abilities in chimpanzees (Povinelli & Eddy, 1996; Itakura, et. al, in press).

Call, J., Hare, B., & Tomasello, M. (1998). Chimpanzee gaze following in an object-choice task. Animal Cognition, 1, 89-99.

Itakura, S., Agnetta, B., Hare, B., & Tomasello, M. (in press). Chimpanzees use human and conspecific social cues to locate hidden food. Developmental Science.

Povinelli, D., & Eddy, T. (1996). Factors influencing young chimpanzees recognition of "attention." Journal of Comparative Psychology, 110, 336-345.

Tomasello, M., Hare, B., & Agnetta, B. (1999) Chimpanzees follow gaze geometrically. Animal Behaviour, 58, 769-777.

Hare, Brian

Department of Biological Anthropology, Harvard University

11 Divinity Avenue, Cambridge, MA 02138

bhare@fas.harvard.edu