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…

From early in life, children learn to perform actions on the objects in their environments. Although children learn from observing others' actions, actively engaging with the material to be learned can be important for learning. This study tested whether instruction that included opportunities for children to be active supported toddlers' action…