Entertainment media have always made good scapegoats for negative behaviors among young people. In the 1950s, lots of people blamed comic books for kids acting badly [source: CBS News]. In the 1960s, rock 'n' roll made kids do drugs [source: Paul]. In the '80s, heavy-metal music was causing teens to commit suicide [source: Tewksbury]. The 1999 Columbine massacre, with its unprecedented number of victims, might have ushered in the official age of "blame the video games."
There is some evidence to support a relationship between playing violent video games and behaving violently. A 2000 study published in the Journal of Personality and Social Psychology had college students play video games and then engage in a competition that ended with the winner punishing the loser with a loud audio blast. The students who had played a violent video game punished their opponents for longer than the students who played a nonviolent game [source: American Psychological Association].
A meta-analysis reported in the journal Psychological Science in 2001 noted several common conclusions among previous video-game studies, notably reports of a "fight or flight" response in children playing video games. Their heart rates and blood pressures increased, and their adrenal glands released adrenaline. Real-life violence triggers the same physiological responses. The analysis concluded that the studies "clearly support the hypothesis that exposure to violent video games poses a public-health threat to children and youths."
Other physical links were revealed in a 2006 study at the Indiana University School of Medicine, this time regarding brain activity. Researchers looked at the brains of 44 kids immediately after they played video games. Half of them played a nonviolent game, and half played a violent game. The brain scans of the violent-game group showed increased activity in the amygdala, which stimulates emotions, and decreased activity in the prefrontal lobe, which regulates inhibition, self-control and concentration. These increases didn't show up on the scans of the nonviolent-game group.
Whatever the factors, the evidence for some kind of connection is compelling. Today's "school shooters" certainly do seem to share a love of violent video games. But, as Villanova University psychology professor Patrick Markey explained in U.S. News & World Report in April 2013, 97 percent of adolescents play video games. "It could similarly be argued that bread consumption predicts school shootings, because most school shooters likely consumed a bread product within 24 hours before their violent attacks."