Psychology is the science of the psyche or mind (Hebb, 1974). By definition, psychology has been the study of individuals, particularly the mental processes and behavior of individuals or, in the case of social psychology, nonfamilial groups of individuals. Therefore, psychology has had no explicit theory about family structure or functioning. Aspects of theories in psychology that do address the family have been extensions of theories about the individual; that is, family variables, especially parent-child relationships, have been used to predict outcomes in the individual's development, personality, or behavior pattern. Of course, the way these family variables were conceptualized and measured reveals implicit theories about coupling and families within the various subdisciplines of psychology.