This study of 59 children (ages 1-3) at risk for severe mental retardation suggests that subjects exhibited repetitive motor behaviors topographically similar to those exhibited in typical infant development; there were significant age differences in expression of these behaviors; and a small percentage of these children exhibited atypical…

Two children (ages 10 and 12) with severe mental retardation were trained to make the same response when presented with 2 initially unrelated stimuli and then trained to make a new response when presented with 1 of those stimuli. Children were then assessed on their response to the second stimulus. Results of the tests for the emergent…

This study of social referencing in parent/child dyads found that 20 nondisabled children (ages 6-27 months) showed evidence of behavior regulation, touching positive-message toys more often than fearful-message toys, whereas a group of 20 children (ages 15-54 months) with developmental delays did not. (Author/JDD)

The social development of a female rhesus monkey was followed from birth until death, age 32 months. The monkey had an extra autosome and was hydrocephalic. The monkey showed serious motor deficiencies, delayed social development, poorly established dominance relationships, and heavy dependence on mother and kin. The monkey was, however, well…

This paper reviews research on disturbances of children with developmental delays and handicaps in responding to complex stimuli, suggesting that such disturbances may deleteriously influence behavioral/neurophysiological development. Intervention programs for teaching children with autism a generalized set to use in responding to complex…

Adults with mental retardation (n=22,740) were studied to investigate age-related changes in functioning and their relation to subsequent mortality. Individuals with Down syndrome, compared to non-Down syndrome individuals with mental retardation, were at earlier and higher risk for adaptive regression whether prevalence, incidence, or mortality…

This study found that 16 preschoolers with Down's syndrome attained higher age equivalents and standard scores in "socialization" than did 16 preschoolers with autism. Adaptive age equivalent was positively related to chronological age for children with Down's syndrome in all domains, but only in "communication" for children with autism.…