There are more general things that have been linked to violence. I've heard that US soldiers in WWII sometimes had a hard time looking at the enemy and pulling the trigger, but there was much less of this inhibition in Vietnam. There was also the infamous My Lai massacre in Vietnam, and this was before there were any video games at all. One risk factor is witnessing violence; for example, a boy who sees his father hitting his mother is more likely to hit his wife when he grows up. Could violent video games have a similar effect - making violence seem more normal and acceptable? I don't know. The study did say that when parents were involved, kids were less likely to become violent. Perhaps another issue is the need for role models to show kids how to resolve conflicts.