Effects of age on the adaptive behavior of institutionalized individuals with Down syndrome

Institutional residents with Down syndrome (N = 413) were matched on sex, length of hospitalization, and IQ with an equal number of residents in other diagnostic categories. The subjects were divided into six age groups, from 0 to 19 to 60 to 69 years, and comparisons were made on 62 items of the Client Development Evaluation Report. Significant effects of age were found on 38 items and of diagnosis, on 19 items, but significant Age X Diagnosis interaction effects on only 4 items. Thus, there was little evidence that age differentially affects the adaptive behavior of mentally retarded persons with and without Down syndrome.