When I began graduate study of psychology in the early 1950s, I entered a theoretically divided house. Most experimental psychologists could be described as neo-behaviorists, studying classical and operant conditioning, paired associate learning, psychophysics, and the like. The data collected were measures of physical events in animals and humans. Theories described connections between objective measures, as in other physical sciences; inferences about mediating mental phenomena (hypothetical constructs) were highly controversial and prompted vigorous debate.

Clinical psychology was, however, a very different matter.

Based on the great need for mental health workers, occasioned by the flood of psychiatric casualties among war-veterans in the aftermath of World War II, an increasing proportion of university psychologists were treating patients and training students in clinical practice. The then general view of mental disorder was, as for psychiatry, dominated by the theories of Sigmund Freud, his colleagues, and disciples.

In the 1950s, clinical evaluation did not involve the measurement of behavior or physiology, but depended on analysis of patients’ symptom reports and personal memories, gathered in a prolonged series of interviews – a “talking cure.” The therapist's interpretations were intended to uncover patients’ hidden (unconscious) foci of distress. Treatment was achieved when the patients gained emotional “insight”: a conscious realization of the dark motives determining their dysfunctional behavior.

In graduate school, I took the sequence of clinical courses and associated practicum, along with the required program in experimental psychology. I vividly recall a curious sense of “split-personality” that developed during these studies. In experimental psychology, careful objective measurement, statistical analysis, and rigorous theory-testing characterized one-half of my days; for the clinical half, I was like an acolyte training for a new priesthood, learning to sense the presence of frightening, invisible forces, buried in patients’ monologues.

The trajectory of my subsequent work as a scientist, I believe, stemmed from the initial uneasiness with this divide – that there could be two psychologies, casually tolerated by both camps, so different in how knowledge was acquired – with fundamentally opposed views as to what constituted meaningful data.

In 1958, I joined the psychology faculty at the University of Pittsburgh. In that same year, a book was published that had a profound effect on my future research career: Psychotherapy by Reciprocal Inhibition, written by Joseph Wolpe.