Date of Award


Document Type


Degree Name

Master of Science (MS)




This study investigated the effects of some of the variables operating on the acquisition and extinction of avoidance behavior by mildly retarded adolescent girls. The subjects observed were 20 patients of Parsons State Hospital and Training Center. All the subjects were 15 years of age or older and none of them had reached her twenty-first birthday at the time that the experiment was run. They had adaptive behavior levels of I, II or III.

The subjects were randomly assigned to one of two replications and to one of two experimental conditions (extinction and control). All the subjects were brought into a room and given avoidance instructions. If avoidance responding did not occur after the aversive stimulus, white noise with an intensity of 99 decibels, had been presented the experimenter prompted the subject. Prompting was continued until avoidance responding began. After 20 minutes the subjects were allowed to leave and were paid a nickel. After this first session, four more 'avoidance sessions with no special instructions were given. After this, two more sessions were given to all the subjects with the noise lowered to an intensity of 75 decibels. In the last two sessions the now lowered noise remained on continuously for the extinction subjects, while the control subjects could still avoid it by responding. Each subject was paid a nickel at the end of each session.

No replication effects of any kind were found. There were no session effects during acquisition. The extinction subjects decreased their response rate significantly more than the control subjects. The main contribution of this study is considered to be the introduction of an extinction procedure that achieves its purpose relatively fast; however, it should be more directly compared to the traditional procedure that simply stops the aversive stimulus regardless of the subjects behavior, before definite conclusions can be made.


viii, 54 leaves : ill., photos. ; 28 cm. Bibliography: leaves 53-54.

Included in

Psychology Commons


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