According to a new study, violent video games tend to make children more violent in real life. The study, which appears in the November issue of the journal Pediatrics, studied children in the U.S. and Japan and reported that children who played a lot of violent video games exhibited more aggressive behavior months later than their peers who did not play. Previous studies on the same lines could not differentiate if violent games made children aggressive or were already violent children more likely to play violent games.

Dr. Craig A. Anderson, Ph.D., of Iowa State University in Ames, and his colleagues examined children and teen's video game habits and how they related to their behavior three to six months later. Three groups of kids were involved 181 Japanese student’s ages 12 to 15; 1,050 Japanese students aged 13 to 18; and 364 U.S. kids’ ages 9 to 12. The researchers examined the favorite video games and how often they were played. In every group the researchers noted that children who were more exposed to violent video games became more aggressive than the children who had less exposure. This factor stood even when earlier aggressive behavior in the children was taken into account.

Dr. L. Rowell Huesmann, director of the Research Center for Group Dynamics at the University of Michigan's Institute for Social Research in Ann Arbor said, The findings are "pretty good evidence" that violent video games do indeed cause aggressive behavior. "When you're exposed to violence day in and day out, it loses its emotional impact on you," Huesmann said. "Once you're emotionally numb to violence, it's much easier to engage in violence."

Dr. Cheryl K. Olson, co-director of the Center for Mental Health and the Media at Massachusetts General Hospital in Boston said, "It's not the violence per se that's the problem, it's the context and goals of the violence. I think there may well be problems with some kinds of violent games for some kinds of kids," Olson said. "We may find things we should be worried about, but right now we don't know enough."

Dr. David Walsh, president of the National Institute on Media and the Family, a Minneapolis-based non-profit said, "It doesn't necessarily mean that because a kid plays a violent video game they're immediately going to go out and beat somebody up," Walsh says. "The real impact is in shaping norms, shaping attitude. As those gradually shift, the differences start to show up in behavior."

The study concludes, "Playing violent video games is a significant risk factor for later physically aggressive behavior. The research strongly suggests reducing the exposure of youth to this risk factor."