Watching violent television programmes or video games can make teenage boys more prone to aggressive behaviour, according to a study that strengthens the case for curbing the amount of violence depicted in film and video.
The research, published in Social Cognitive and Affective Neuroscience, used a medical scanner to investigate the brain activity of 22 boys aged between 14 and 17 while they viewed four-second video clips of violent scenes taken from 60 different videos.
"We found that as the boys were exposed to more violent videos over time, their activation in brain regions concerned with emotional reactivity decreased and that was reflected in the data from the [brain scanner] and in the skin-conductance responses," said Jordan Grafman who carried out the study at the US National Institute of Neurological Disorders and Stroke in Bethesda, Maryland.
"The important new finding is that exposure to the most violent videos inhibits emotional reactions to similar aggressive videos over time," Dr Grafman said. The study suggests that exposure to violent videos will make an adolescent less sensitive to violence, more accepting of violence, and more likely to commit aggressive acts, he added.