Differential Susceptibility Effects: The Interaction of Negative Emotionality and Sibling Relationship Quality on Childhood Internalizing Problems and Social Skills

Whereas socialization influences in early childhood have been linked to children’s emerging internalizing problems and prosocial
behavior, relatively few studies have examined how NE might moderate such associations in both advantageous and maladaptive
ways. Furthermore, more research is needed to evaluate the impact of sibling relationships as an influential socialization
influence on these child outcomes. In the current study we examined how NE might differentially moderate the associations
between quality of relationships with siblings and both internalizing problems and social skills at school entry. NE moderated
the effects of positive and destructive sibling relationship quality on child internalizing problems. Specifically, for boys
high on NE, more positive sibling relationship quality predicted fewer internalizing problems, but more destructive sibling
conflict predicted more internalizing problems. NE also moderated the effects of destructive sibling conflict on child social
skills. For boys high on NE, destructive sibling conflict predicted fewer social skills. Boys high on NE appear to show greater
susceptibility to the effects of sibling socialization on child outcomes, relative to boys low on NE. The implications of
these interactions are discussed with respect to differential susceptibility theory.