Parity is one source of automatic reinforcement that increases the probability of verbal behavior that conforms to models provided by the verbal community. Parity as a conditioned reinforcer could explain the acquisition of grammar in the absence of direct, explicit reinforcement. This possibility has been explored in previous research on…

This study sought to further investigate the effects of an observational intervention for two participants on the reinforcing property of pieces of string. Pre-observational intervention data showed that the neutral stimuli (strings) did not function to reinforce two participants' responding to a performance task or learning three new skills that…