This prospective longitudinal study focused on self-regulatory, social–cognitive, and parenting precursors of individual differences in children’s peer-directed aggression at early school age. Participants were 1993-year-old boys and girls who were reassessed following the transition to kindergarten (5.5–6 years). Peer aggression was assessed in preschool and school settings using naturalistic observations and teacher reports. Children’s self-regulation abilities and theory of mind understanding were assessed during a laboratory visit, and parenting risk (corporal punishment and low warmth/responsiveness) was assessed using interview-based and questionnaire measures. Individual differences in children’s peer aggression were moderately stable across the preschool to school transition. Preschool-age children who manifested high levels of aggressive peer interactions also showed lower levels of self-regulation and theory of mind understanding, and experienced higher levels of adverse parenting than others. Our main finding was that early corporal punishment was associated with increased levels of peer aggression across the transition from preschool to school, as was the interaction between low maternal emotional support and children’s early delays in theory of mind understanding. These data highlight the need for family-directed preventive efforts during the early preschool years.

An explanatory model for children’s development of disruptive behavior across the transition from preschool to school was tested. It was hypothesized that child effortful control would mediate the effects of parenting on children’s externalizing behavior and that child sex would moderate these relations. Participants were 241 children (123 boys) and their parents and teachers. Three dimensions of parenting, warm responsiveness, induction, and corporal punishment, were assessed via maternal report when children were 3 years old. Child effortful control at age 3 was measured using laboratory tasks and a mother-report questionnaire. Mothers and teachers contributed ratings of child externalizing behavior at age 6. Results showed that the hypothesized model fit the data well and that the pattern of associations between constructs differed for boys and girls. For boys, parental warm responsiveness and corporal punishment had significant indirect effects on children’s externalizing behavior three years later, mediated by child effortful control. Such relations were not observed for girls. These findings support a sex-differentiated pathway to externalizing behavior across the transition from preschool to school.

We examined the development of children’s inhibitory control from toddlerhood to early school-age (i.e., ages 2 to 7.5 years), investigated the effects of the Family Check-Up on the growth of inhibitory control, and explored whether such effects transferred to the school context. Participants were 731 low-income children (49 % female). Results indicated that parental reports of inhibitory control showed positive, nonlinear increase with the growth decelerating over time. Moreover, children in the intervention condition demonstrated higher levels of growth in parental ratings of inhibitory control compared to the control condition. More importantly, the intervention had indirect effects on teacher reports of children’s self-control and oppositional defiant behavior as well as examiner ratings of self-control through its promotion of growth in inhibitory control. The findings are discussed with respect to implications for more specifically targeting the promotion of self-regulation in early childhood in addition to reduction in early problem behavior.

We examined associations of proactive parenting, child verbal ability, and child effortful control within the context of a randomized prevention trial focused on enhancing parenting practices in low‐income families. Participants (N = 731) were assessed annually from the age of two to five, with half randomly assigned to the Family Check‐Up (FCU). Results indicated that the child's verbal ability at the age of three partially mediated the influence of proactive parenting at the age of two on children's effortful control at the age of five. More importantly, the FCU indirectly facilitated children's effortful control by sequentially improving proactive parenting and children's verbal ability. The findings are discussed with respect to taking a more integrative approach to understanding early predictors and the promotion of self‐regulation in early childhood.