Behavioral characteristics of high- and low-IQ autistic children.

The authors are developing the Behavior Observation Scale to objectively differentiate autistic, normal, and mentally retarded children aged 30--60 months. They describe operational definitions and procedures and report data on the frequency of selected behaviors among 114 children. Prior studies have revealed that to assess the clinical significance of behaviors in autistic children, both frequency of occurrence per subject and the number of children exhibiting the behaviors must be considered concurrently.