Psychiatrists tend to derive their theoretical and therapeutic orientations from either of two models of human behavior: the psychological and the biological. Psychoanalytic theory represents the predominant psychological approach to behavior, whereas neuroscience provides the fundamentals of the biological approach. The former approach explains behavior on the basis of psychodynamics and past life events, whereas the latter approach emphasizes neurophysiological explanations of behavior. Accordingly, Hollingshead and co-workers found two distinct therapeutic orientations among New Haven psychiatrists in the 1950s (Hollingshead and Redlich, 1958; Myers and Bean, 1968). Those who had a psychoanalytic orientation had received little training in the basic biological sciences during their years of specialization. On the other hand, psychiatrists