The experimental psychologist Albert Bandura, with his focus on social-cognitive processes, came to influence BT in a variety ways, par- ticularly in that his rigorous scientific approach allowed for the consid- eration of unobservable mental states and their relationship to social behaviors. Social skills training grew to incorporate role plays with the therapist, often making use of modeling as a means of learning—a cen- tral concept for Bandura (Bandura, 1969).Armed with the concepts of conditioning, operant-learning, extinc- tion through exposure, relaxation training, assertion training, and mod- eling, clinicians increasingly made use of behavioral interventions in psychotherapy. By the mid-1960s, such clinical practices became wide- spread, leading to further developments that brought BT into maturity. Psychiatric hospitals employed token economies for schizophrenic pa- tients and mentally retarded patients (Kazdin & Bootzin, 1972). These social learning programs relied heavily on principles of reinforcement as well as social skills training, which include assertion training. Be- haviorally focused interventions for children and adolescents with autism, hyperactivity, conduct disorder, aggressiveness, and other be- havior problems began to flourish (Bornstein & Kazdin, 1985). Addi- tionally, training programs for parents were developed, to help parents modify the contingencies in children’s environments (Ross, 1981). As technology evolved, forms of relaxation training came to incorporate the use of physiological measures that provided continuous feedback to clinicians and patients in a process known as biofeedback (Schwartz& Beatty, 1977). Increased interest also developed more broadly in the intersection between physical health and mental health, leading to the development of behavioral medicine (Pomerleau, 1979), an approach to both medicine and psychology that rely on a biopsychosocial model, rather than the medical model of disease (Engel, 1977).