Finally! No need to worry about your kid (or boyfriend) going on a ballistic shooting rampage in a corporation owned by Italian mob bosses. According to this Yahoo! Games article, a couple Harvard Med School brainies have found in a two-year study that kids/pre-teens/teens who have a "casual relationship" with violent video games will unlikely act out because of what they've seen or experienced in their games. The research has even been penned into a book aptly titled, Grand Theft Childhood: The Surprising Truth About Violent Video Games and What Parents Can Do. The authors suggest that parents should take a look at the bigger picture and find out what other factors are buggin' their kids out (e.g., they're being bullied at school, bad grades, or even obsessive gaming habits).
In other words, stop placing the blame on the games--that's bad parenting.