The development of gestural communication in young chimpanzees

Plooij (Action, Gesture and Symbol, Academic Press 1978; Before Speech, C.U.P. 1979) described some intentionally-produced communicatory gestures used by one-year-old chimpanzees on the Gombe Stream Reserve. The current study investigated the use of this type of gesture at later developmental periods. Subjects were five infant and juvenile chimpanzees (Pan troglodytes) living in a semi-natural group at the Yerkes Regional Primate Center Field Station. On the basis of naturalistic observations, three stages in the development of communicatory gestures were determined: (1) One-year-old infants used some gestures, but only in an immature form and only with their mothers or with peers; (2) Two-year-olds produced more gestures which were clearly intentional and conventional (they waited for a response), and they directed them to all group members; (3) Three-year-olds used a wider variety of gestures, and they supplemented them with a "gaze-alternation" behavior which indicated even more clearly the goal of the communication. Many of the gestures used by infants and juveniles were not used by adults, thus indicating a significance confined to specific developmental periods. This contradicts the commonly-held assumption (e.g. Van Lawick-Goodall, 1967) that the developmental process is one in which young chimpanzees come gradually to learn a pre-existing set of adult communicatory gestures. From this and other evidence, it is argued that, while some of the gestures are learned observationally, many are learned through a process of "direct convention-alization" between animals, and others rely on both of these processes. © 1985 Academic Press Inc. (London) Limited.

Duke Scholars

Author Michael Tomasello Psychology & Neuroscience