. . . in the case of private stimuli, one may teach a child to say “That hurts” in agreement with the usage of the community by making the reinforcement contingent upon public accompaniments of painful stimuli (a smart blow, tissue damage, and so on). The connection between public and private stimuli need not be invariable; a response may be conditioned with merely periodic reinforcement and even in spite of an occasional conflicting contingency. The possibility of such behavior is limited by the degree of association of public and private stimuli which will supply a net reinforcement sufficient to establish and maintain a response. (pp. 420-421)
