Date of Award


Degree Name

Master of Arts



First Advisor

Dr. Jack L. Michael

Second Advisor

Dr. Paul Mountjoy

Third Advisor

Dr. David Lyon

Access Setting

Masters Thesis-Open Access


Eighteen institutionalized school-age and adult subjects with severe/profound developmental disabilities were evaluated for the effects of self-selected reinforcement for correct responding on their I.Q. scores when tested with the Stanford-Binet Intelligence Scale (Terman & Merrill, 1960) or the Leiter International Performance Scale (Arthur, 1952). Subjects were tested under both standard and reinforcement conditions. The results indicated that overall, subjects when tested under reinforcement conditions showed a significant increase in mean I.Q. scores when compared with the same subjects tested one month previously under standard conditions. Several features of the data reveal intriguing results with regard to subjects and related preexisting or predetermined variables, including age, psychotropic medication, and test type. Results and implications of the data for I.Q. testing of institutionalized severely and profoundly retarded individuals were discussed.