The Theory and Practice of Group Psychotherapy by Irvin D. Yalom, Molyn Leszcz

instruct members in their pregroup interviews or in the first group sessions; they may, repeatedly during the meetings, ask for all members’ reactions to another member or toward a group issue; they may ask why conversation is invariably directed toward the therapist; they may refuse to answer questions when addressed; they may ask the group to engage in exercises that teach clients to interact—for example, asking each member of the group in turn to give his or her first impressions of every other member; or therapists may, in a much less obtrusive manner, shape behavior by rewarding members who address one another—therapists may nod or smile at them, address them warmly, or shift their posture into a more receptive position. Exactly the same approaches may be applied to the myriad of other norms the therapist wishes to inculcate: self-disclosure, open expression of emotions, promptness, self-exploration, and so on.
    Therapists vary considerably in style. Although many prefer to shape norms explicitly, all therapists, to a degree often greater than they suppose, perform their tasks through the subtle technique of social reinforcement. Human behavior is continuously influenced by a series of environmental events (reinforcers), which may have a positive or negative valence and which exert their influence on a conscious or a subliminal level.
    Advertising and political propaganda techniques are but two examples of a systematic harnessing of reinforcing agents. Psychotherapy, no less, relies on the use of subtle, often nondeliberate social reinforcers. Although few self-respecting therapists like to consider themselves social reinforcing agents, nevertheless therapists continuously exert influence in this manner, unconsciously or deliberately. They may positively reinforce behavior by numerous verbal and nonverbal acts, including nodding, smiling, leaning forward, or offering an interested “mmm” or a direct inquiry for more information. On the other hand, therapists attempt to extinguish behavior not deemed salubrious by not commenting, not nodding, ignoring the behavior, turning their attention to another client, looking skeptical, raising their eyebrows, and so on. In fact research suggests that therapists who reinforce members’ pro-group behavior indirectly are often more effective than those who prompt such behavior explicitly. 5 Any obvious verbal directive from therapists then becomes especially effective because of the paucity of such interventions.
    Every form of psychotherapy is a learning process, relying in part on operant conditioning. Therapy, even psychoanalysis, without some form of therapist reinforcement or manipulation is a mirage that disappears on close scrutiny. 6
    Considerable research demonstrates the efficacy of operant techniques in the shaping of group behavior. 7 Using these techniques deliberately, one can reduce silences 8 or increase personal and group comments, expressions of hostility to the leader, or intermember acceptance. 9 Though there is evidence that they owe much of their effectiveness to these learning principles, psychotherapists often eschew this evidence because of their unfounded fear that such a mechanistic view will undermine the essential human component of the therapy experience. The facts are compelling, however, and an understanding of their own behavior does not strip therapists of their spontaneity. After all, the objective of using operant techniques is to foster authentic and meaningful engagement. Therapists who recognize that they exert great influence through social reinforcement and who have formulated a central organizing principle of therapy will be more effective and consistent in making therapeutic interventions.
    The Model-Setting Participant
    Leaders shape group norms not only through explicit or implicit social engineering but also through the example they set in their own group behavior. 10 The therapy group culture represents a radical departure from