Aggressive Behaviors in Young Siblings: Associations with Executive Functions and Maternal Characteristics.

Aggressive behaviors in early childhood are associated with multiple undesirable outcomes, including juvenile delinquency, academic failure, and substance abuse. This investigation employed a family study design to examine child, mother and sibling predictors of early-emerging aggressive behaviors. These predictors included several indices of executive functioning within children, depression symptoms and education level of mothers, and inhibitory control (IC) of siblings. The sample consisted of 95 families (191 children; boys = 100) with at least two, typically developing children between 30 and 66 months of age (M(age) = 45.93 months, SD = 12.40). Measures included laboratory-assessed working memory and IC, parent-reported aggressive behaviors, as well as self-reported maternal depression symptoms and education. Results revealed that children showed substantial sibling similarity in aggressive behaviors. Using multilevel regression analyses, low child IC and greater maternal depression symptoms were associated with increased child aggressive behaviors. Child working memory, maternal education, and sibling IC did not uniquely predict child aggressive behaviors. Moderation analyses revealed an interaction between maternal depression symptoms and maternal education, such that the effect of depression symptoms on child aggressive behaviors was particularly evident amongst highly educated mothers. The current analysis moved beyond a main effects model of maternal depression and extended previous findings on the importance of child IC to aggressive behaviors by using a multiple-child-per-family framework. A promising direction for future research includes assessing whether efforts to increase child IC are successful in reducing child aggressive behaviors.