Preschool boys who watch violent television become markedly more aggressive and anti-social as they grow older, found a study by Seattle researchers in one of the largest examinations so far of such connections, the Seattle Times reports. Girls appear impervious to the effects of television violence, a finding that has the researchers puzzled. The study, which focused on years of data for 330 children around the U.S., found that each hour of violent shows viewed per day by boys ages 2 to 4 increased their aggression threefold, as reported by their parents five years later. It adds to a large body of evidence that kids learn from what they watch, the study’s lead author said.
“Speaking broadly, the link between on-screen violence and subsequent violent behavior is as strong as evidence that smoking causes lung cancer,” said Dr. Dimitri Christakis, a pediatric researcher with Seattle’s Children’s Hospital Research Institute and a professor at the University of Washington School of Medicine. The paper was published in the November issue of Pediatrics. The fact that girls weren’t affected by the TV violence should be studied more closely, Christakis said. He attributes it to the possibility that boys are biologically more prone to aggression, along with differing social norms for girls’ behavior.