Age-related change in processing speed has been linked directly to increases in reasoning as well as indirectly via increases in the capacity of working memory (WM). Most of the evidence linking change in speed to reasoning has come from cross-sectional research; in this article we present the findings from a 2½-year longitudinal study of 277 6-…

Relational reasoning is an essential component of fluid intelligence, and is known to have a protracted developmental trajectory. To date, little is known about the neural changes that underlie improvements in reasoning ability over development. In this event-related functional magnetic resonance imaging (fMRI) study, children aged 8-12 and adults…

A study of the responses made to problems selected from Raven's Progressive Matrices showed differences in the kinds of errors typically made by eighteen-year-old students. Nine problems were used and the 68 subjects were told to draw their answers on the answer sheets. There were two trials per puzzle. A classification system, devised for errors,…