Compared the performance of 29 institutionalized cultural-familial mental retardates on Piagetian conservation tasks. Examined the effects of age, sex, and degree of retardation on conservation performance. (BD)

Do stage-related patterns of early cognitive development reported for normally developing children also characterize at-risk and handicapped children when mental age organization of data is used? Mental age predicted Piagetian-based cognitive levels one to three but did not predict highest-level symbolic functioning in 95 handicapped children.…

A study of 700 children (ages 5-12) investigated whether children's conceptions of and expectations of friendship are determined by chronological age or by mental age. Results found children of differing intellectual abilities pass through the five conception stages of friendship at different ages and at different rates. (Contains 4 references.)…

Down Syndrome children (N=229), aged 1-83 months, from Australia, Canada, and Germany were tested using the Bayley Scales of Infant Development. Test performances on the Bayley's Mental and Motor scales were not dissimilar, leading to the conclusion that young Down Syndrome children from different countries with relatively comparable standards of…

Adolescents, ages 11-12 and 13-14, were tested for maturity of judgment about stability-change situations and about time perspective. (CP)

A case study of a pair of extremely deprived twin boys focuses on their verbal communication. Talkativeness alone was not regarded as a measure of intelligence, but attention was paid to the less talkative twin's greater use of imaginative speech. Speculations are made on the evolutionary role of creative speech. (IS)