Joint attention and imitative learning in children, chimpanzees, and enculturated chimpanzees

In this study we compared the nature of the joint attentional interactions that occurred as chimpanzees and human children engaged with a human experimenter (E). Subjects were three chimpanzees raised mostly with conspecifics (mother-reared), three chimpanzees raised in a human-like cultural environment (enculturated), and six 18-month-old human children. Of particular interest were possible differences between the two groups of chimpanzees that might have resulted from their differ ent ontogenetic histories. Observations were made as subjects participated in an imitative learning task involving a number of novel objects. Variables coded were such things as subjects' looks to the object, looks to E, the coordination of such looks in periods of joint engagement with E, and gestural attempts to direct E's attention or behavior (declaratives and imperatives). Results showed that enculturated chimpanzees were most similar to human children in social interactions involving objects, for example, in their attention to the object in compliance with E's request, their joint attentional interactions during less structured periods, and their use of declarative gestures to direct E's attention to objects. They were not similar to children, but rather resembled their mother-reared conspecifics, in the duration of their looks to E's face. A positive relation between subjects'joint attentional skills and their imitative learning skills was found for both chimpanzee and human subjects. It is concluded that a human-like sociocultural environment is an essential component in the development of human-like social-cognitive and joint attentional skills for chimpanzees, and perhaps for human beings as well.