Despite the importance of self-control for well-being and adjustment, its development from early childhood to early adolescence has been relatively understudied. We addressed the development of mother-reported self-control in what is likely the largest and longest longitudinal twin study of the topic to this day (N = 1889 individual children with…

The non-cognitive skills self-control and grit are often considered predictors of school performance, but whether this relationship is causal remains unclear. We investigated the causality of this association using a twin design. Specifically, we evaluated the direct impact of self-control and grit on school performance, while controlling for…

Sleep is important for child development. Sleep problems in early childhood are associated with negative outcomes across numerous domains, including executive control, internalizing and externalizing psychopathology, and social competence (Astill et al., 2012; Hysing et al., 2016; Spruyt et al., 2019). Little research has focused on moderators…