The emergence of social cognition in three young chimpanzees.
We report a series of 10 studies on the social-cognitive abilities of three young chimpanzees. The studies were all ones previously conducted with human infants. The chimpanzees were 1-5 years of age, had been raised mostly by humans, and were tested mostly directly by a familiar human experimenter. First, in a longitudinal investigation with repeated measurements from a social-cognitive test battery, the three young chimpanzees were similar in many ways to human infants; the major difference was a total lack of attempts to share attention with others either in joint attentional interactions or through declarative gestures. Second, in imitation-based tests of the understanding of intentional action, the chimpanzees, like human infants, showed an understanding of failed attempts and accidents; but they did not pay attention to the behavioral style of the actor or the actor's reasons for choosing a particular behavioral means. Third, in tests of their understanding of visual perception, the chimpanzees followed the gaze direction of a human to an out-of-sight location behind a barrier and gestured more to a human who could see them than to one who could not; but they showed no understanding that perceivers can focus their attention on one thing, or one aspect of a thing, within their perceptual fields for a reason. Finally, in tests of joint intentions and joint attention, the chimpanzees showed no ability to either reverse roles with a partner in a collaborative interaction or to set up a joint attentional framework for understanding the communicative intentions behind a pointing gesture. Taken together, these findings support the idea that the early ontogeny of human social cognition comprises two distinct trajectories, each with its own evolutionary history: one for understanding the basics of goal-directed action and perception, common to all apes, and another for sharing psychological states with others in collaborative acts involving joint intentions and attention, unique to the human species.
Tomasello
Michael
M
Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany. tomas@eva.mpg.de
Carpenter
Malinda
M
D000339:Affect; D000367:Age Factors; D000818:Animals; D001288:Attention; D001522:Behavior, Animal; D002755:Choice Behavior; D003071:Cognition; D003142:Communication; D005260:Female; D005868:Gestures; D033182:Intention; D008297:Male; D002679:Pan troglodytes / Q000523:psychology*; D011340:Problem Solving; D012938:Social Perception; D013028:Space Perception