My interest in nonverbal behavior has remained constant for over 15 years. I think this has been the case because nonverbal behavior has proved a very fascinating and challenging topic. Others might suggest that I am just a slow learner. With enough time in any area, however, one begins to feel that he or she has some special insights to offer to others. About the time that I was struck with that thought, approximately two and a half years ago, I was developing the first version of my sequential functional model of nonverbal exchange. It seemed to me that the func­ tional model might provide a very useful framework for a book discussing and analyzing nonverbal behavior. I did not want (nor do I think I had the patience) to write a comprehensive review of research on nonverbal behavior. Other works, such as Siegman and Feldstein's (1978) edited Nonverbal Behavior and Commu­ nication, and Harper, Wiens, and Matarazzo's (1978) Nonverbal Communication: The State of the Art, have provided excellent reviews of the research on nonverbal behavior. Instead, what I have tried to do in this book is to use nonverbal behavior as a vehicle for discussing social behavior. In a very real sense, this analysis of nonverbal behavior is a means to an end, not an end in itself. A consequence of this approach is that this review is a selective one, unlike the comprehensive works mentioned earlier.