The Role of Parenting and Cortisol in Children's Early Peer Relationships.

Prior theoretical and empirical work demonstrates associations between peer victimization and later aggressive behavior. To better understand this link in early childhood, the present study examined children's basal cortisol levels and parental warmth as moderators of the association between peer victimization in the fall of preschool (T1) and changes in aggression from T1 to T2 (preschool spring). Participants were 262 3- to 5-year-old children (M age = 4.30 years, SD = 0.31). At T1, children provided samples of salivary cortisol and parents reported on their warm parenting practices. Teachers reported on children's physical and relational peer victimization at T1 and physical and relational aggression at T1 and T2. Greater T1 relational victimization was associated with significant increases in relational aggression from T1 to T2. Children with low levels of basal cortisol displayed decreases in physical aggression when experiencing high levels of physical victimization at T1. Associations between victimization and later aggression were not significantly moderated by parental warmth. These results may help identify children who may benefit from intervention to prevent the development of aggressive behavior and subsequent academic and psychological challenges.