Specificity hypothesis of a theory of mind deficit in early childhood autism

Abstract

In order to test the hypothesis that a theory of mind deficit is specific for autism, the present study presents the first replication of the Sally-Anne test (Baron-Cohen, Leslie & Frith, 1985) in the German-speaking countries. The Sally-Anne test was administered to 16 autistic, 24 probands with Down's syndrome and 20 normal preschool prosands. The intelligence of the autistic group and that with Down's syndrome was measured by the CPM/SPM. In addition, the ADI-R was used with the principal caregivers of the autistic and Down's syndrome subjects. With regard to the clinical diagnosis, theory of mind deficit turned out to be not specific for autism. Six of 16 (37.5%) autistic subjects passed the theory of mind tasks. Thus performance in the autistic group surpassed that of both control groups. Out of 16 autistic subjects, autism could be confirmed in only 8 on the basis of the ADI-R diagnostic criteria, only one of whom showed a theory of mind. The autistic individuals with a theory of mind differed significantly in their mean IQ from those without this ability. Spectrum and specificity of a theory of mind deficit in autism remain controversial. For further research it seems important to administer the ADI-R during the diagnostic process. The findings suggest that the clinical diagnosis of autism is not precise enough to distinguish between autism and nonautistic mental handicap.