ince there was no main effect of gender (no gender difference) with respect to antisocial behavior at T1, the gender-specific finding does not seem to be due to a very low level of such behavior in girls. A possible explanation, therefore, could be sex-specific socialization: boys have been shown to display more aggressive, confrontational behavior in their social interactions with friends and with nonfriends than girls (Denton and Zarbatany, 1996 and Maccoby and Jacklin, 1980).