Individual Differences in Intelligence and Working Memory: A Review of Latent Variable Models

The purpose of the current review is to examine individual differences in i ntelligence and working memory capacity. The emphasis is on latent variable models and theoretical frameworks that connect interindividual differences in behavior with intraindividual psychological processes. Our review suggests that intelligence and working memory capacity are strongly correlated and that the shared variance is primarily due to the fluid reasoning component of intelligence and mechanisms of cognitive control in working memory. We conclude that research on intelligence and working memory is a rare successful example of the unification of experimental and differential psychology. Finally, we argue that general ability models of intelligence that posit a unitary source of variance are not consistent with contemporary research and should be fairly rejected.