There is no evidence that punishment ultimately reduces a tendency to respond. Its principal effect is to convert the behavior, or the circumstances under which the behavior characteristically occurs, into a conditioned aversive stimulus. Any behavior which reduces such stimulation—such as any behavior which is incompatible with or otherwise displaces punished behavior, either in its incipient or final stages—is automatically reinforced. In punishing one response, then, we automatically provide for the reinforcement of responses which are incompatible with it. (p. 166)
