A comparative study of infantile autism and specific developmental receptive language disorders. III. Discriminant function analysis.

A psychometric, observational, and interview study was undertaken with 47 boys, aged 4 1/2 to 10 years, with nonverbal IQs of 70+ and a severe developmental disorder of language comprehension. Separate discriminant function analyses, based on behavioral, language, or cognitive features, showed little overlap between clinically defined autistic and dysphasic subgroups. Moreover, the discrimination could be made as clearly on language or cognitive characteristics as on social or behavioral critera. Language abnormalities and behavioral features also intercorrelated within the autistic subgroup. It is concluded that autism and dysphasia differ in important ways and that a cognitive deficit is an essential part of the syndrome of autism.