Alternative theories of the origin of derived stimulus relations

Two theories of derived stimulus relations are discussed. Sidman's primary process theory holds that contingencies establish the discriminative stimulus, the response, and the reinforcement as members of the same equivalence class. This position suggests a continuity of processes between humans and nonhumans and requires only a very modest change in traditional views concerning principles of behavior. Hayes, Barnes-Holmes and Roche also maintain that equivalence is a function of contingencies. However, they maintain that equivalence is only one of many relational frames that are developed through learning multiple examples. Moreover, once relational frames are developed, these frames may change the effects of direct contingencies. They state that if their position is valid "we must rethink all of behavioral psychology as it applies to verbal organisms." Their position implies a discontinuity between the behavior of humans and nonhumans. These two different perspectives suggest quite different research agendas. The research agenda suggested by Hayes et al. is primarily directed toward the study of human behavior, while the research agenda of Sidman suggests the study of both human and nonhuman behavior.