Abstract
A simple‐structure factor analysis of test data from a sample of 148 fifteen‐year‐old children in Norway was carried out. Broad factors were interpreted to represent visualization, speediness, and fluency, as well as fluid and crystallized intelligence. The results are consistent with the factor distinctions as hypothesized by Cattell, but analyses of the developmental differentiation of fluid and crystallized intelligence raise some doubts about Cattell's interpretation of these dimensions.