Shaping

A gradual, behavior modification technique in which successive approximations to the desired behavior is rewarded.

Shaping, or behavior-shaping, is a variant of operant conditioning. Instead of waiting for a subject to exhibit a desired behavior, any behavior leading to the target behavior is rewarded. For example, B. F. Skinner (1904-1990) discovered that, in order to train a rat to push a lever, any movement in the direction of the lever had to be rewarded, until finally, the rat was trained to push a lever. Once the target behavior is reached, however, no other behavior is rewarded. In other words, the subject behavior is shaped, or molded, into the desired form.

Although rejected by many orientations within the field of psychology, behavioral techniques, particularly shaping, are widely used as therapeutic tools for the treatment of various disorders, especially those affecting verbal behavior. For example, behavior shaping has been used to treat selective, or elective, mutism, a condition manifested by an otherwise normal child's refusal to speak in school.

Therapists have also relied on behavior shaping in treating cases of severe autism in children. While autistic children respond to such stimulus objects as toys and musical instruments, it is difficult to elicit speech from them. However, researchers have noted that behavior shaping is more effective when speech attempts are reinforced than when speech production is expected. When unsuccessful efforts to produce speech are rewarded, the child feels inspired to make a greater effort, which may lead to actual speech.

While recognizing the effectiveness of behavior shaping in the laboratory and in therapy, experts, particularly psychologists who do not subscribe to behaviorism, have questioned the long-term validity of induced behavior change. For example, researchers have noted that people have a tendency to revert to old behavior patterns, particularly when the new behavior is not rewarded any more. In many cases, as Alfie Kohn has written, behavior-shaping techniques used in school, instead of motivating a child to succeed, actually create nothing more than a craving for further rewards.