THE EFFECTS OF INCENTIVES ON THE PERFORMANCE OF DEFECTIVE IMBECILES

The present experiment was designed to inquire into the effects of different incentive conditions on the performance of male imbeciles. In particular the aim was to clarify further the effect of goal‐striving and encouragement on performance in uncontaminated experimental groups. The experiment was suggested, first, because the previous results in the field had been equivocal, and secondly, since inquiry into the trainability of imbeciles had been encouraging. The latter results suggested how imperative it was to determine the best incentive conditions to be employed in any experimental workshop in which such work was being undertaken. Forty‐eight imbeciles were used. On the basis of their first performance on the Leg Persistence Test they were divided into four matched groups of 12 subjects each and asked to perform under different motivating conditions. There were four incentive conditions used—‘Control’, ‘Goal’, ‘Competition’ and ‘Encouragement’. The experiment continued at the rate of one trial per day over twenty trials. As far as possible each of the four groups was tested on the same day for the equivalent trial number. The four groups were also found to be closely matched on the basis of intelligence. There can be little doubt that incentives improve the performance of imbeciles on a dull routine task. In contrast, under conditions of indifference their performance deteriorates. No support was gained for Gordon's contention that imbeciles respond to goal conditions of motivation better than when encouraged. In the present study competition and encouragement appear to be the best conditions of motivation.