Frequent exposure to violent video games increases the likelihood that children and teens will engage in aggressive behavior themselves, new research indicates.
The study of more than 3,000 children found that habitually playing games such as "Call of Duty" and "God of War" might alter their view of their real-world environment and peers, the researchers said.
"[Violent gaming] basically changes a child's or adolescent's personality in some sense, so that they start to see their world in a more aggressive way," said study co-author Craig Anderson, director of the Center for the Study of Violence at Iowa State University.
"They start to expect people to behave more aggressively toward them, and they tend to see aggressive solutions as being more appropriate for solving problems," Anderson said.
More than 90 percent of American kids play video games, many of which portray violence in a fun framework free of negative consequences, the researchers said. Because of these large numbers, research such as this has significant implications, they said.
Still, parents shouldn't panic, Anderson said.
"Playing a violent video game isn't going to take a healthy kid who has few other risk factors and turn him into a school shooter," he said. "But it is a risk factor that does drive the odds for aggression up significantly."
Anderson said there are many other known risk factors for aggression, such as growing up with parents who are visibly aggressive or living in a violent neighborhood.
The children enrolled in the study, which was published online March 24 in the journal JAMA Pediatrics, came from six primary and six secondary schools in Singapore. All were between 8 and 17 years old, and nearly three-quarters were boys.
For three years, the students were surveyed annually about the time they spent playing video games and about the nature of their favorite games.
In addition, the children discussed their feelings of empathy and aggression, and were asked about any past aggressive behaviors. For example, children were asked if they felt it was OK to respond to certain provocative situations by hitting someone, whether they ever thought about hurting a peer and whether seeing someone else who was upset bothered them.
By stacking violent video game habits up against aggressive thought patterns and behavior, the investigators determined that during the three-year study period kids with a lot of exposure to violent video games were more likely to engage in aggressive behavior.
This link seemed to result from a lasting increase in aggressive thinking, the researchers said. That included a rise in aggressive fantasies, and a growing tendency to attribute hostile motives to others.
The shifts in thinking associated with heavy use of violent games occurred for both girls and boys, even when parents monitored their child's gaming habits. The changes were also found to be independent of a child's initial aggressiveness, the study found.
The researchers also said having feelings of empathy didn't seem to dampen the link between violent gaming and aggression, and the link was seen more or less across all age groups.
The authors said more research is needed to better understand the effects of playing video games that glorify brutality. "[But] at least one major reason aggressive behavior went up in children is because violent video games seemed to increase a child's violent thought patterns," Anderson said.
Richard Gallagher, director of the Parenting Institute at the New York University Child Study Center, said he wasn't surprised by the findings.
"Research data with persons of all ages has consistently indicated that playing violent video games does change attitudes and does possibly alter behavioral tendencies," he said. "And it's looking like it shifts kids to what's considered to be a kind of disturbed and biased thinking."
This is important for people to know in terms of public policy and parenting, Gallagher said.
"These kinds of games are not benign," he said. "They might not cause all kids to get involved with negative and aggressive behavior, but they do push them more in that direction."
For more on kids and media exposure, visit the U.S. National Institutes of Health.