A Sequential Model of the Contribution of Preschool Fluid and Crystallized Cognitive Abilities to Later School Achievement

The present study documented in two distinct population-based samples the contribution of preschool fluid and crystallized cognitive abilities to later school achievement in primary school and examined the mediating role of crystallized abilities in this sequence of predictive associations. In both samples, participants were assessed on the same fluid and crystallized abilities at 63 months (sample 1) and 73 months (sample 2), and then regarding their school achievement in grade 1 to grade 6. Both preschool fluid and crystallized abilities were found to significantly predict school achievement, but only in the early school years. Through path analyses controlling for sex, maternal education and family income, preschool crystallized abilities mediated the association between early fluid abilities and later school achievement in the early grades of school. Crystallized abilities predicted early school achievement beyond fluid abilities, but not in the later grades. These results support the importance of early interventions aimed at both preschool fluid and crystallized abilities to prevent children from developing future school difficulties.