Learned experience is an important determinant of aggression in humans. Elicitors of aggression such as personal insults, status threats, and the presence of weapons are all learned sources of aggressive behavior. Further, aggressive actions are often followed by rewards and are therefore likely to be repeated. Children learn that aggression can enable them to control resources such as toys and parental attention. Children also learn aggression by observing others behave aggressively. The violent behavior of some teenage gangs provides its younger members with aggressive role models. Children whose parents discipline with physical force tend to use more physical aggression when interacting with others, and parents who abuse their children were typically abused children themselves. The influence of the mass media, especially television, on promoting aggressive behavior is not yet well understood, but a growing body of research evidence indicates that watching violent entertainment is linked to subsequent aggression in humans.