Gestural behavior between mothers and young children was hypothesized to be important in the acquisition of communicative competence. It was presumed that a typology of gestural function could assess non-verbal behavior. Data consisted of sound film samples of feeding and bathing events of three subject pairs. Initially the children ranged in age from 19-21 months. The children exceeded their mothers in the use of gestural behavior at each time period and children's gestural behavior significantly decreased over time. Although maternal gestural behavior generally decreased over time, an increase at Time IV occurred. Mothers used gesture to assess and reinforce existing knowledge. Analysis of non-verbal behavior indicated that dissimilar gestural functions are expressed by similar motor acts and, conversely, that dissimilar motor acts express similar functions. Analysis of gestural functions subsumed equivalent to complementary verbal functional categories showed that children's gestures support linguistic skills. Some gestures were believed to map symbolic behavior, other non-symbolic gestures demonstrated reliance on non-verbal behavior to acquire skills of communicative competence. (Author)