“…The prevalence of certain practices within a group reflects a type of group norm, often referred to as a descriptive norm (Cialdini, Kallgren, & Reno, 1991) which can affect peer interactions (Bronfenbrenner, 1977). The frequency or normativeness of behavior among peer groups serves as a guideline for appropriate behavior (Berkowtiz, 2003; Cialdini et al, 1991; Miller & Prentice, 1994; Shaw, 1981). Past research has supported that children who are exposed to environments in which aggression is prevalent or normative tend to act aggressively in suit (Henry, Guerra, Huesmann, Tolan, VanAcker, & Eron, 2000; Kuppens, Grietens, Omghena, Michiels, & Subramanian, 2008; Nipedal, Nesdale, & Killen, 2010; Thomas, Bierman, & The Conduct Problems Prevention Research Group, 2006), reflecting the perception that such behavior is acceptable.…”