Does playing violent videogames make you more aggressive? The debate has been raging for years, and one man thinks he has the answer.

The state of the art in videogame-violence research is conducted in a room the size of a broom closet in Ames, Iowa. Inside Room C of Lagomarcino Hall, Dr. Craig Anderson, head of the department of psychology at Iowa State University, employs old-fashioned methodologies to study the psychological effects of the latest in digital entertainment. In his study of aggressive thoughts, he calculates, for example, how long it takes a subject, after playing a violent videogame, to recognize words like murder on a screen; he measures how loudly a gamer deploys a noisemaker to retaliate against someone who’s just blasted him with sound.

In one experiment, designed to assess the effect of violent games on so-called helping behaviors, participants sit in a room filling out a questionnaire after playing a first-person shooter. An argument breaks out in the hallway. It’s only a recording, but it sounds serious and a victim is left whimpering for help. The violent gamers take longer to get up and offer assistance than a control group of nonviolent gamers.

What Anderson has learned is that people who play violent games for as little as 20 minutes exhibit aggressive thoughts and actions and less of a willingness to help others. Statistically, he says, these correlations are as strong as the link between secondhand smoke and cancer.

Some critics complain that Anderson’s old-fashioned experiments (not to mention the inability of any laboratory to take the overall cultural context of games into account) undermine his conclusions. After all, the whole point of entertainment is to arouse an audience, argues Jeffrey Goldstein, a social psychologist at Holland’s University of Utrecht who has also submitted expert testimony before Congress. Anything that raises the heart rate, he says, ”from running around the block to watching a pornographic movie, can lead to aggressive behavior.”

Anderson knows a thing or two about aggression. The youngest son of an Indiana farmer, he had a bad temper that got him into his share of trouble. After graduating from high school, he joined the Army Reserve and trained as a mechanic, though he never saw combat. His first brush with videogames occurred in 1976 when, pursuing his graduate studies at Stanford, he discovered Pong. But it was only years later, after he’d become interested in research related to television and film violence, that he had his lightbulb moment, realizing no one had yet applied the same rigorous methodologies to study the emerging realm of digital entertainment.

Although Anderson says he strives to maintain a purely scientific role, his research is being used to set public policy. He consulted for and testified before the St. Louis County Council regarding an ordinance that requires adult consent for buying M-rated games and forces arcades to cordon off mature games with a curtain or wall, similar to the adult section of a video store. Anderson’s work also helped reduce the sentences of two separate juvenile killers who’d played videogames just prior to shooting their playmates to death. ”What I was able to do,” says attorney Ray Jackson, who helped his defendants beat first-degree murder charges, ”is make the jury believe the first shot was in fact an accident because of the videogames.”