IDENTIFICATION AND MODIFICATION OF A RESPONSE-CLASS HIERARCHY

We evaluated the effects of extinction and negative reinforcement on t he latency of response-class members following requests made to a 15-y ear-old female with moderate mental retardation and autism. A function al analysis showed that the class members (screams, aggression, and se lf-injury) were escape maintained. Informal observations suggested tha t these topographies generally occurred in the sequence listed above a nd therefore may have been hierarchically related. A therapist provide d escape from demands contingent on a specific member of the class to determine the effects on the latency of the members' occurrence. Resul ts showed that the latencies occurred in a predictable order. In addit ion, we expanded the response class to include a vocal response that w as functionally equivalent to other members. Findings are discussed re garding the covariation and sequence of response-class members and tre atment development.