The study of nonverbal behavior has substantially grown in importance in social psychology during the past twenty years. In addition, other disciplines are increas ingly bringing their unique perspectives to this research area. Investigators from a wide variety of fields such as developmental, clinical, and social psychology, as well as primatology, human ethology, sociology, anthropology, and biology have system atically examined nonverbal aspects of behavior. Nowhere in the nonverbal behavior literature has such multidisciplinary concern been more evident than in the study of the...