Differentiation of intelligence refers to changes in the structure of intelligence that depend on individuals' level of general cognitive ability (ability differentiation hypothesis) or age (developmental differentiation hypothesis). The present article aimed to investigate ability differentiation, developmental differentiation, and their…

This article presents three studies, two of them longitudinal, which investigated the relations between age, processing speed, working memory (WM), and fluid intelligence ("g[subscript f]") from 4 to 16 years of age. Structural equation modeling showed that speed was a powerful covariate of age ([approximately] - 0.6 to - 0.7) from 4 to 13 years,…

The purpose of this research was to investigate the cognitive abilities that explain reading comprehension across childhood and early adulthood. Drawing from the standardization sample of the Woodcock-Johnson III, analyses were conducted with large samples at age levels spanning early childhood to early adulthood: 5 to 6 (n = 639), 7 to 8 (n =…

The study investigates the effects of intelligence, perceptual speed and age on intraindividual growth in attentional speed and attentional accuracy over the course of a 6-minute testing session. A sample of 193 subjects completed the Advanced Progressive Matrices and the Vienna Matrices Test representing intelligence, the tests Alertness and…

Reviews research on development of children's beliefs about intelligence; proposes that this development represents simultaneous processes of concept acquisition and theory building. Discusses research foci on children's definitions of intelligence, beliefs about the component structure of intelligence, criteria children use to evaluate ability,…

A study of effects of age and schooling in grades five and six on raw scores from a variety of general ability tests found that schooling: (1) is the major factor underlying the increase of intelligence test scores as a function of age; and (2) has a larger effect on verbal than nonverbal tests. (RH)

The relation of domain knowledge to achievement, and changes in this relation that occur with age and type of memory task, are discussed. First, different mechanisms through which domain-specific knowledge relates to strategy use in memory tasks are summarized. Then, empirical evidence that indicates direct effects of the knowledge base on memory…

The author reviews cross-sectional and longitudinal studies on the status of intelligence in the aging, and finds conflicting conclusions: (1) intelligence does decline as persons grow older; (2) only some aspects decline while others improve; and (3) intelligence does not decline. Certain factors are adduced to suggest that such…

This paper is a preliminary report of a project designed to determine the family and other environmental factors which are associated with effective functioning in children from low income environments. The purpose of the project was to determine the strengths in poverty situations which should be capitalized on in developing educational programs…