Speech skill levels and prevalence of maladaptive behaviors in autistic and mentally retarded children: a statistical study.

Forty-seven autistic and 128 mentally retarded children, ages 6 to 14, from a special school were assessed in terms of nine maladaptive behaviors and speech skill levels. The results indicated that the group of the mentally retarded children with withdrawal had significantly lower speech skill levels than the group of those without withdrawal, and the group of the autistic children with self-injury had significantly lower speech skill levels than the group of those without self-injury.