The study examined whether the development of receptive language lags behind nonverbal cognitive development in school age persons with mental retardation. Results indicated that the relationship between receptive language and mental age varied across mental age levels, linguistic forms, and individuals at the same mental age for listeners with…

Sixteen individuals with autism and sixteen with Down's Syndrome, aged 10-29, were matched for verbal mental age. The groups' scores did not differ on the Vineland Adaptive Behavior Scales. However, the adaptive skills of Down's Syndrome individuals kept pace with mental age, while the skills of autistic subjects did not change. (Author/JDD)