Parents should keep a close watch on what kind of media content their children consume as researchers have found that teenagers exposed to TV and film violence and high levels of household conflict are at risk of engaging in aggressive behaviours.
The findings, published online in the journal Aggressive Behavior, suggest that parental monitoring help to protect against aggressive behaviour.
"It was quite interesting that for adolescents who had high levels of media violence exposure, family conflict, impulsivity and sensation-seeking, parental monitoring still continued to provide a protective effect against aggressive tendencies," said lead author Atika Khurana, Professor at the University of Oregon in the US.
The findings are based on an online survey of some 2000 teenagers aged 14-17.
The participants were asked what shows they had watched, how many times they viewed each, and whether they had engaged recently in a physical fight, face-to-face bullying and cyberbullying as measures of aggression.
To measure family conflict, the teenagers were asked if their home life involved criticism, hitting each other, cursing, arguing and throwing things when angry.
Other questions probed parental supervision of media use, such as restricting and forbidding the viewing of violence and adult content.
The researchers found that media violence alone was a strong risk factor for aggression, even when the adolescents were low in all the other risk factors.
"The effect is no doubt greater if you also have other risk factors such as family conflict and impulsivity, but it is nonetheless significant even for those at lower risk in other categories," Khurana said.
She, however, cautioned that parental intervention in media viewing needs to be age appropriate.
Actions that restrict or forbid viewing of violent media works best with younger adolescents but can be counterproductive with older teens, Khurana said.