David Grossman, a retired Army psychologist, believes that violent video games are teaching our kids to kill. Grossman first became aware of this issue while conducting research for his Pulitzer Prize-nominated book, On Killing, which recounts the U.S. Army's solution to an interesting problem: as many as 85 percent of soldiers did not fire their weapons during World Wars I and II.

The reason for the soldiers' reluctance, according to Grossman, was psychological: "Hardwired into the brains of most healthy members of most species is a response against killing their own kind." In order to deal with this problem, the army desensitized soldiers to the act of killing by having them practice shooting human-shaped targets made of wood. As technology improved, however, the military began using video games to simulate the killing of other human beings.

Grossman believes that modern video games like Doom and Grand Theft Auto operate along the same principles, and have the same effect. In other words, they are chillingly effective at desensitizing teens to the act of killing other human beings. David Walsh, director of the National Institute on Media and the Family, agrees: "What happens when a teen spends a lot of time playing violent video games is [that] the aggression center of the brain activates, but the emotional center of the brain deactivates—exactly the combination that we would not want to see."

As evidence of this claim, Grossman points to a Paducah, Kentucky, native named Michael Carneal. In 1997, then 14-year-old Carneal opened fire in the lobby of his high school, seriously injuring five of his classmates and killing three others. A subsequent police investigation found that Michael's parents had converted their two-car garage into a playroom lined with point-and-shoot arcade games. In other words, a lifetime of playing violent video games had provided Michael with the emotional training needed to kill another human being.

What's even more frightening is that those video games also provided Michael with the physical training needed to use a deadly weapon. Prior to the night before his killing spree, he had never shot an actual pistol. However, when he opened fire on his fellow students, he did so with a surprising degree of accuracy. Grossman explains:

You have kneeling, scrambling, screaming targets. Carneal fires eight shots at eight different targets. Five of them are head shots, the other three [are] upper torso. Now, I have trained the FBI. I have trained Navy SEALS, Green Berets, and Texas Rangers. And when I tell them about this case, they're simply stumped. Nowhere in the annals of law enforcement, military, or criminal history can we find equivalent achievement.