Violent video games tied to teen aggression

NEW YORK (Reuters Health) - Adolescents who play violent video games may become increasingly aggressive over time, a new study of Japanese and U.S. teens suggests.

Researchers found that among three groups of 9- to 18-year-olds followed over several months, those who regularly played violent video games were more likely to get into more and more physical fights over time. The study is among the first to chart changes in gamers' aggressive behavior over time, lending weight to evidence that violent video games can encourage violence in some kids. And it's the first to show that the effects are seen across cultures, researchers report in the journal Pediatrics.

"Basically what we found was that in all three samples, a lot of violent video game play early in a school year leads to higher levels of aggression during the school year, as measured later in the school year -- even after you control for how aggressive the kids were at the beginning of the year," lead researcher Dr. Craig A. Anderson, of Iowa State University in Ames, explained.

An argument has been made that video games cannot be directly contributing to aggression because violence rates are low in Japan where video games are highly popular, Anderson said in a written statement.

"By gathering data from Japan," he said, "we can test that hypothesis directly and ask, 'Is it the case that Japanese kids are totally unaffected by playing violent video games?' And of course, they aren't. They're affected pretty much the same way American kids are.

The findings are based on two separate groups of teenagers from Japan -- 1,231 teens in all -- and 364 9- to 12-year-olds from the U.S. At the outset, participants estimated how often they played violent video games, then their own aggressive behavior was followed for up to six months afterward.

The Japanese teens reported on their own violent behavior using questionnaires, while teachers' and peers' reports were used to estimate the U.S. group's aggressive behavior.

In general, Anderson's team found that kids who habitually played violent video games were more likely than their peers to become increasingly involved in physical fights -- even when their behavior in the months leading up to the study was taken into account.

Of course, not all kids who play aggressive video games act them out in real life. Nor is media violence alone to blame for teenagers' aggression, the researchers point out.

But what these video games may do, the investigators say, is feed the idea that violence is a normal and acceptable way to react to everyday conflicts, like getting bumped in the school hallway. "It is important to realize that violent video games do not create schools shooters," Dr. Douglas A. Gentile, another researcher on the study, said in the statement.

"Violent games are certainly not the only thing that can increase children's aggression," he added, "but these studies show that they are one part of the puzzle in both America and Japan."

SOURCE: Pediatrics, November 2008.