An increasing amount of research demonstrates that children can become more aggressive by playing violent video games. With the increasing popularity of video games (researchers say about 90% of all children between eight and 16 routinely play the games), there is growing concern that virtual violence can lead to real life violence and aggressive tendencies in children.

A new study, authored by Dr. Craig Anderson of Iowa State University, examined the behavior of children in the United States and Japan and compared the amount of time spent playing video games considered to be violent or aggressive in nature.

There have been dozens of studies which have looked at the effects of violent video games, and usually the conclusions of the research get bogged down trying to determine causation — in other words, when children behave aggressively are they doing so as a learned behavior that is influenced by video games, or are children with a more aggressive nature naturally drawn toward playing violent video games?

In the Iowa State study, Dr. Anderson and his team of researchers examined the behavior of children in three months increments in an attempt to show causation. The results showed that the children who were exposed to increased videogame violence during each three-month period of the study showed a marked increase in aggression compared to those who were not exposed to the violent games.

These findings represent the most conclusive evidence to date that video games not only affect the behavior of children, but influence them to behave in more aggressive ways. Experts believe that children are more prone to imitate what they see on television, in movies, and in video games, and that these influences are effectively “teaching” children that aggressive behavior is an acceptable means of conflict resolution.

The researchers also theorize that being exposed to violent video games can cause a general desensitization to violence. Once a child is desensitized to the point of having little emotional response to aggressive behavior, it becomes more likely the child will engage in aggressive behavior in real life.

But many critics argue that video games are just the tip of the iceberg, and that the media is awash with violent and aggressive behavior that can potentially shape attitudes and encourage acceptance of violence.

The new Iowa State study however, makes a very convincing argument that the interaction allowed by video games actually “trains” children to think and react in a more aggressive manner, and that parents need to do a better job of controlling these influences in their children’s lives.