Oddity preference by mental retardates

Three groups of severely retarded and three groups of mildly retarded individuals were given a series of five 10-trial oddity problems under non-reward conditions. The groups were presented with stimulus arrays containing one odd stimulus and two, three, or four identical stimuli. The results indicated that the mildly retarded group responded to the odd object slightly less than 50% of the time, significantly above chance expectancy, whereas the severely retarded group responded to the odd object approximately 33% of the time, significantly above chance expectancy for those groups with three and four identical stimuli. These findings suggest that oddity is a stimulus characteristic to which an approach response is made independent of its concurrent association with reward, and that the stimulus value of oddity differs for mildly and severely retarded Ss.