Emotional disturbance and mental retardation: diagnostic overshadowing.

Two experiments evaluated the effects of the condition of mental retardation on psychologists' impressions of emotional problems of a retarded subject. In Experiment 1 we found that the same debilitating phobia was less likely to be considered an example of a neurosis or an emotional disturbance when the subject also was suggested to be mentally retarded as compared to intellectually average. Experiment 2 provided a conceptual replication of the results of Experiment 1 and extended findings of diagnostic overshadowing to cases involving schizophrenia and personality disorder. The magnitude of these effects did not differ significantly as a function of whether the case description suggested schizophrenia or personality disorder. The results validate the existence of a diagnostic overshadowing phenomenon.