I think it's interesting to note that when you step outside of an experimental setting, and you graph the rate of video game usage (which I assume has been going up over the last ten years) along with the rate of juvenile violent crime (which has been dropping over the last ten years), you get a different picture. I certainly don't mean to imply that violent video games turn us into pacifists, but neither do I see an overall negative effect on society.

As for the article linked ...

Although it's not a popular view in some parts to acknowledge that what we watch can affect our behavior, more and more studies are showing just that. What's more, if it had no effect, TV stations wouldn't be able to charge as much for advertising time, and companies wouldn't spend the money on it.

Well, of course what we watch can affect our behavior. So can what we read and what we hear. To deny that is to imply that nothing can affect our behavior, and I find that notion too absurd to be worth refuting.

But not everything affects our behavior in the same way. If I watch a movie (or play a game) that inspires me to perform kind acts, I'm unlikely to resist that impulse. But if I watch a movie (or play a game) that inspires me to go out and shoot people, I'm likely to resist that impulse (even if the people are bad guys), because that's what reasonably sane, well-balanced people do. If I were so unbalanced that a video game would make me become violent, I would probably also be inspired to violence by rush-hour traffic, long lines at the post office, and some of my students' writing.