A landmark study published in 2003 in Psychological Science by Iowa State Professor Craig Anderson and other academics, which surveyed significant research on the topic up until that point, found “unequivocal evidence” that violent television and films, video games, and music, along with other forms of media violence, increase the likelihood of aggressive and violent behavior in both immediate and long-term contexts. The effects appear more profound when it comes to milder forms of aggression, but they exist for severe forms, too. For example, one study in Anderson’s survey revealed that violent TV exposure at age 14 significantly predicted assault and fighting behavior at 16 or 22 years of age, even after controlling for a host of variables such as family income, parental education, verbal intelligence, and neighborhood characteristics. Anderson’s research also found that large-scale longitudinal studies provide converging evidence linking frequent exposure to violent media in childhood with aggression later in life, including physical assaults and spousal abuse.

Tucson Shooting: Words And Violence | The New Republic.

If this is correct, then we have to be willing to consider the effects of Call of Duty and Grand Theft Auto just as seriously as we consider the effects of Glenn Beck and Sarah Palin. Hard to find people who are willing to take all the media equally seriously, or equally lightly. We pick and choose.