Effects of age and IQ on adaptive behavior domains for children with autism

Researchers have examined adaptive behavior in autism, but few studies have looked for different patterns of adaptive skills according to age and intelligence. Domain scores from the Vineland Adaptive Behavior Scale (VABS) were compared in relation to age and Performance IQ for 72 children and adolescents with autism and 37 nonautistic children and adolescents with mental retardation. Age and IQ were positively related to each of the Vineland domains. Children with autism had lower scores in the socialization domain. An interaction was present between Performance IQ and group: With increasing IQ, children with autism showed smaller increases in social functioning than children with mental retardation. A similar trend was present for daily living skills. Results suggest that (a) the relationship between the two groups' adaptive behavior profiles is stable from preschool age through adolescence, and (b) increasing IQ is associated with less of an increase in certain adaptive skills for children with autism.