Growth models for subtests of the Stanford-Binet Intelligence Scale, 4th edition (R. L. Thorndike, E. P. Hagen, & J. M. Sattler, 1986a, 1986b) were developed for individuals with Down syndrome. Models were based on the assessments of 208 individuals who participated in longitudinal and cross-sectional research between 1987 and 2004. Variation…

Williams syndrome is a rare neurodevelopmental disorder caused by deletion of approximately 25 genes on chromosome 7q11.23. Children with the syndrome evidence large individual differences in both broad language and reading abilities. Nevertheless, as a group, children with this syndrome show a consistent pattern characterized by relative…

The authors report data from a longitudinal study that addresses the relations between working memory capacity and reading comprehension skills in children aged 8, 9, and 11 years. At each time point, the authors assessed children's reading ability, vocabulary and verbal skills, performance on 2 working memory assessments (sentence-span and digit…