A recent study shows a link between violent video games and aggressive behavior in kids and teens. The more the children played violent video games, the more physically aggressive they became.

Regular child and adolescent violent video game use early in the school year predicted later aggressive behavior in a study in both the U.S. and Japan. Researchers monitored the behavior of more than 1,200 students in Japan, ages 12 to 18, and 364 U.S. students, ages 9 to 12.

The study results were similar: habitual violent video game play early in the school year predicted later aggression. The study authors recommend reducing child and teen use of violent video games.