Individuals with late-treated phenylketonuria (PKU) not detected by newborn screening but who followed dietary treatment for at least 12 months before 7 years of age have intelligence quotient (IQ) scores that range from severe impairment to the low-normal range. Among adults with late-treated PKU in California, 85% of those who were born from…

Reviews the history of the developmental study of infants and children at biological risk and appraises the current state of the art. Four research phases during the period from 1920 to the present are identified, each reflecting aspects of the social, political, health, and psychological zeitgeist. (Author/RH)

Compared the spontaneous leg movements of 10 infants with Down Syndrome to those of nondisabled infants matched for chronological age and motor age. Contrary to expectations, no significant difference was found in the frequency of leg movements between the two groups. However, Down Syndrome subjects demonstrated significantly fewer of the most…

Examines differences in habituation in a visual attention task as a function of chronological age, mental age, and handicapping condition. Subjects were 102 children who ranged in age from 3 to 36 months and who were classified as Down Syndrome, cerebral palsied, developmentally delayed, or multiply handicapped. (Author/RH)

Investigates the influence of chronological age, mental age, and handicapping condition on mothers' interactions with their handicapped young children. A total of 111 handicapped children ranging in age from 3 to 36 months and their mothers participated. Infants' general functioning and handicapping conditions were related to maternal…