Tracking executive function across the transition to school: a latent variable approach.

This longitudinal study of executive function (EF) addressed three questions. These concerned: (i) the validity of EF as a latent construct underpinning performance at ages 4 and 6 on tests of planning, inhibitory control, and working memory; (ii) developmental change in EF across these time-points, which straddled children's transition to school; and (iii) verbal ability and family income as predictors of base-line individual differences and variation in the slopes of EF development. Confirmatory factor analyses of data from a socially diverse sample of 191 children supported the validity of a single EF construct at both time-points; a MIMIC (multiple indicators, multiple causes) model showed equally good fit for boys and girls. Latent growth models demonstrated that verbal mental age and family income predicted EF intercepts, but EF slopes were only related to verbal mental age. Across the transition to school, less able children (but not children from low income families) showed greater gains in EF than their peers.