Genes Unite Executive Functions in Childhood

Abstract

Individual differences in children's executive functions (EFs) are relevant for a wide range of normal and atypical psychological outcomes across the life span, but the origins of variation in children's EFs are not well understood. We used data from a racially and socioeconomically diverse sample of 505 third- through eighth-grade twins and triplets from the Texas Twin Project to estimate genetic and environmental influences on a Common EF factor and on variance unique to four core EF domains: inhibition, switching, working memory, and updating. As has been previously demonstrated in young adults, the Common EF factor was 100% heritable, which indicates that correlations among the four EF domains are entirely attributable to shared genetic etiology. Nonshared environmental influences were evident for variance unique to individual domains. General EF may thus serve as an early life marker of genetic propensity for a range of functions and pathologies later in life.

Keywords: behavior genetics; cognitive ability; cognitive development; individual differences.

Figure 1

Hierarchical multivariate twin model for additive genetic (A), shared environmental (C), and non-shared environmental (E) contributions to EF performance. Numbers on arrows represent standardized factor loadings. Our model controls for age-effects at the level of the first-order factors (Inhibition, Switching, Working Memory, and Updating). Because the purpose of this analysis was to understand the relative contributions of genetic and environmental influences to individual differences, as separate from age-related differences, the loadings of the first-order factors have been standardized relative to their age-independent variance. Bolded paths and estimates indicate significance at p < .05.