The age of detection of autism varies and may be linked to differences in the severity of disturbance and any associated retardation. Symptom intensity, overall language level, age of recognition of first disturbances and level of psychological development were examined in 222 children with pervasive developmental disorder with a mean age of 5 years. Results showed a positive correlation between language level and psychological development as well as between language level and intensity of symptoms. The central position of language in psychological development is discussed.