Scientists have warned for years that playing violent video games causes players to become more aggressive.
The researchers found that participants who played “Call of Duty,” “Hitman,” “Killzone” and “Grand Theft Auto,” were more aggressive – than participants who played a nonviolent game. In addition, for participants that had not played many violent video games before completing the study, playing a violent game in the lab caused a reduced brain response to photos of violence – an indicator of desensitization. Moreover, this reduced brain response predicted participants’ aggression levels: the smaller the brain response to violent photos, the more aggressive participants were. Participants who spent a lot of time playing violent video games before the study showed small brain response to violent photos, regardless of which type of game they played in the lab.