To the extent that a society values violence, attaches prestige to violent conduct or defines violence as normal or legitimate, the values of individuals within that society will develop accordingly. Worldwide, those countries with high income inequality have the highest homicide rates. The best predictor of future aggression is past aggressive behaviour.
Aggressive children tend to grow into aggressive adults.
Violent behaviour does not appear to be an inherited characteristic. 6, Television viewing may be associated with subsequent aggression in some viewers.