media AO1

• Hours watching TV in childhood associated with adult convictions for aggressive and violent crimes (Robertson et al. 2013 followed 1,000 New Zealanders).
• Bandura et al replicated their Bobo doll study, but this time children watched a film of an adult model beating the doll. Children again imitated the model's behaviour closely, demonstrating that social learning can operate through media as well as face to face.
• A meta-analysis of about 200 studies found a significant positive correlation between viewing TV/film violence and sexual assault. However, TV and film violence accounted for only 1-10% of variance in children's aggressive behaviour, suggesting a minor effect on aggression for TV and film compared with other sources.
• Evidence that computer games have a more powerful effect than traditional screen-based media because the gameplay is active, viewers are passive. Gameplay is directly rewarding, so it is operant conditioning.
• For ethical reasons, participants are not exposed to violence. Therefore, studies used tailor-competitive reaction time tasks, giving blasts of white noise at chosen volumes to a non-existent opponent.
• Bartholomew and Anderson found that students playing a violent game, Mortal Kombat, for 10 minutes gave higher volumes of white noise than students who played a non-violent golfing game. Several measures of aggression are positively correlated with time spent playing violent games. The link is so well established that, in DeLisi et al.'s view, aggression should be considered a public health issue and computer game violence a risk factor.