Nonverbal communication has been referred to as "body language" in popular culture ever since the publication of Julius Fast's book of the same name in 1970. However, researchers Mark Knapp and Judith Hall (1997, p. 5) have defined nonverbal communication as follows: "Nonverbal communication refers to communication effected by means other than words." This definition does not exclude many forms of communication, but it implies that nonverbal communication is more than body language. However, determination of the exact boundaries of the field is a point of contention among scholars.

Nonverbal communication is an area of study that straddles many disciplines—sociology, psychology, anthropology, communication, and even art and criminal justice. Each of these fields tends to focus on a slightly different aspect of nonverbal communication. For example, psychology might focus on the nonverbal expression of emotions; anthropology might focus on the use of interpersonal space in different cultures; and...