“…These findings suggested that risky peers had a stronger mediating effect from negative personal traits to violence against students for male students. It is possible that boys are more likely than girls to be influenced by at-risk peers (Alexander et al, 2001;Bollmer et al, 2005;Heinze, Toro, & Urberg, 2004;Papalia et al, 2009;Selfhout, Branje, & Meeus, 2008). If boys with positive attitudes toward violence and poor impulsive controls affiliate with their peers with similar personal characteristics, they may be more likely than girls to reinforce their learning of violent behavior in school (Capaldi, Dishion, Stoolmiller, & Yoerger, 2001;Heinze et al, 2004;Selfhout et al, 2008;Solomon, 2006;Sutherland, 1947;Sutherland and Cressy, 1978).…”