Intraindividual variability (IIV) in cognitive speed, or moment-to-moment changes in ability, is a developmental phenomenon indicative of neurological integrity that increases gradually across adulthood. Past research has shown that IIV negatively covaries with cognitive performance, in which higher IIV at one occasion is associated with poorer…

The etiology of individual differences in general verbal ability, verbal learning and letter and category fluency were examined in two independent samples of 9- and 18-year-old twin pairs and their siblings. In both age groups, we observed strong familial resemblance for general verbal ability and moderate familial resemblance for verbal learning,…

Latent growth models were applied to data on multitrial verbal and spatial learning tasks from two independent studies. Although significant individual differences in both initial level of performance and subsequent learning were found in both tasks, age differences were found only in mean initial level, and not in mean learning. In neither task…

Aptitude by treatment interactions are investigated in the context of paired associate learning. Individuals are grouped by preference for visual or verbal items on classifying lists of paired associates and these groups are used to predict performance on criterion lists. (DG)

Reading encompasses a wide range of verbal processes, among them such simple verbal processes as word decoding, letter recognition, name retrieval, and semantic access. The question is whether simple verbal processing differences are adequate to account for general reading ability differences. Across different verbal domains and different ages,…