school violence. The Constitutional Rights Foundation suggests long-term exposure to gun violence, parental alcoholism, domestic violence, physical abuse of the child, and child sexual abuse teaches children that criminal and violent activities are acceptable. Harsh parental discipline is associated with higher levels of aggressiveness in youth. There is some evidence indicating that exposure to television violence and, to a lesser extent, violent video games is related to increased aggressiveness in children, which, in turn, may carry over into school. Straus adduced evidence for the view that exposure to parental corporal punishment increases the risk of aggressive conduct in children and adolescents. Straus's findings have been contested by Larzelere and Baum rind. A meta-analysis of the vast literature on corporal punishment, however, indicates that corporal punishment is related to poorer outcomes in children and youth. The methodologically soundest studies indicate "positive, moderately sized associations between parental corporal punishment and children's aggression." Gershoff found that the trajectory of mean effect sizes (the size of the effect of corporal punishment on children's problem behavior) was curvilinear with the largest mean effect size in middle school (M = 0.55; on average the mean of corporal punishment group was more than half a standard deviation higher than the mean of the non-punishment group) and slightly smaller effect sizes in elementary school (M = 0.43) and high school (M = 0.45). Gerald Patterson's social interactional model, which involves the mother's application and the child's counter-application of coercive behaviors, also explains the development of aggressive conduct in the child. In this context, coercive behaviors include behaviors that are ordinarily punishing (e.g., whining, yelling, hitting, etc.). Abusive home environments can inhibit the growth of social cognitive skills needed, for example, to understand the intentions of others. Short-term longitudinal evidence is consistent with the view that a lack of social cognitive skills mediates the link between harsh parental discipline and aggressive conduct in kindergarten. Longer-term, follow-up research with the same children suggests that partial mediating effects last until third and fourth grade. Hirschi's (1969) control theory advances the view that children with weak affective ties to parents and school are at increased risk of engaging in delinquent and violent behavior in and out of school. Hirschi's cross-sectional data from northern California high-school students are largely consistent with this view. Findings from case-control and longitudinal studies are also consistent with this view. Neighbourhood environment Neighbourhoods and communities provide the context