Stability and change in broad and narrow factors of intelligence from ages 12 to 15 years.

A battery of cognitive tests was administered in the 6th grade (12-year-olds) and again in 9th grade (15-year-olds) to a sample of 225 boys and 242 girls. In the 8th grade, the same students answered an inventory about reading activities. Hierarchical confirmatory factor models were fitted to the test data from each of the 2 occasions, defining a General Intelligence factor and residual factors representing Crystallized Intelligence and General Visualization. Results indicate high stability for the general factor (.92 to .94) and for the residual of the General Visualization factor