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,…

We examined whether fluid intelligence (Gf) is better predicted by the storage capacity of active memory or by the effectiveness of executive control. In two psychometric studies, we measured storage capacity with three kinds of task which required the maintenance of a visual array, the monitoring of simple relations among perceptually available…

This study explored the controversy surrounding working memory: whether it is a unitary system providing general purpose resources or a more differentiated system with domain-specific sub-components. A total of 348 participants completed a set of 6 working memory tasks that systematically varied in storage target contents and type of information…

Sex differences in the latent general and broad cognitive abilities underlying the Differential Ability Scales, Second Edition were investigated for children and youth ages 5 through 17. Multi-group mean and covariance structural equation modeling was used to investigate sex differences in latent cognitive abilities as well as changes in these…

This study analyzes the interplay of four cognitive abilities--reasoning, divergent thinking, mental speed, and short-term memory--and their impact on academic achievement in school in a sample of adolescents in grades seven to 10 (N = 1135). Based on information processing approaches to intelligence, we tested a mediation hypothesis, which states…

Although it is well established that preterms as a group do poorly relative to their full-term peers on tests of global cognitive functioning, the basis for this relative deficiency is less understood. The present paper examines preterm deficits in core cognitive abilities and determines their role in mediating preterm/full-term differences in IQ.…

Recent evidence suggests the existence of multiple cognitive mechanisms that support the general cognitive ability factor (g). Working memory and processing speed are the two best established candidate mechanisms. Relatively little attention has been given to the possibility that associative learning is an additional mechanism contributing to g.…

This study investigated intellectual development in 4-7 years old Greek and Chinese children. They were examined on speeded performance, working memory, reasoning, and self-awareness tasks in order to investigate possible effects of learning the Chinese logographic system on possible differences in intellectual development between these ethnic…

Investigates the relationship between three factors of working memory (storage and processing, relational integration, and supervision) and four factors of intelligence (reasoning, speed, memory, and creativity) using structural equation models. Relational integration predicted reasoning ability at least as well as the storage-and-processing…

This study investigated the structure and development of processes involved in "g." One hundred and forty children, about equally drawn among primary school grades 1-6 were examined by four types of Stroop-like speeded tasks addressed to processes of increasing complexity (i.e., speed of processing, perceptual discrimination, perceptual control,…

The relationship between working memory, intelligence and problem-solving is explored. Wittmann and Suss [Wittmann, W.W., & Suss, H.M. (1999). Investigating the paths between working memory, intelligence, knowledge, and complex problem-solving performances via Brunswik symmetry. In P.L. Ackerman, R.D. Roberts (Ed.), "Learning and individual…

The purpose of this study was to clarify the relationship between attention, components of working memory, and reasoning. Therefore, twenty working memory tests, two attention tests, and nine intelligence subtests were administered to 135 students. Using structural equation modeling, we were able to replicate a functional model of working memory…

This paper examines the relationship between span memory [e.g., immediate memory, short-term memory (STM), simple span] and general ability ("g") though a reanalysis of two data sets [Christal, R. E. (1959). "Factor analytic study of visual memory." "Psychological Monographs: General and Applied," 72 (13, Whole No. 466); Kelley, H.P. (1964).…

This study examined the phenotypic and genotypic relationship between working memory speed (WMS) and working memory capacity (WMC) in 12-year-old twins and their siblings (N = 409). To asses WMS all children performed a reaction time task with three memory loads from which a basic mental speed measure and the derived slope were used. WMC was…

Most psychometric tests of spatial ability are paper-and-pencil tasks at the ''figural'' scale of space, in that they involve inspecting, imagining or mentally transforming small shapes or manipulable objects. Environmental spatial tasks, such as wayfinding or learning the layout of a building or city, are carried out in larger spaces that…