Based on the findings of extant literature, we expected significant links between nominated best friends’ and children's own behavior. Specifically, it was predicted that children who nominated best friends with higher levels of antisocial behavior at Time 1 (T1) would themselves be rated as more antisocial at T1. It was also expected that children who nominated best friends with higher levels of antisocial behavior at T1 would show a greater increase in their own antisocial behavior one year later (T2), compared to those who nominated less antisocial best friends. Moreover, children with antisocial best friends at T1 were expected to be less prosocial at T1 and to show a greater decrease in prosocial behavior from T1 to T2 than other children. Although previous findings regarding the potential effects of prosocial friends are sparse, it was expected that children who nominated highly prosocial best friends at T1 would be rated as more prosocial and less antisocial themselves at T1. It was further predicted that children with highly prosocial best friends at T1 would show a greater increase in prosocial behavior, and a greater decrease in antisocial behavior from T1 to T2, compared to those with less prosocial best friends at T1.