Teenage boys who play violent video games for hours on end may become desensitized to the brutality, a small new study finds.
The research focused on 30 boys, aged 13 to 15, who were divided into two groups. One group typically played violent video games for three or more hours a day (high exposure) while the other group played such games for no more than an hour a day (low exposure).
The researchers monitored the boys' reactions after playing a violent game ("Manhunt") and a nonviolent cartoon game ("Animaniacs"). They played each game for two hours on different evenings.
Differences between the boys' reactions emerged later in the night after gaming. During sleep, the boys in the low-exposure group who played the violent game had faster heart rates and poorer quality of sleep than those in the high-exposure group. The boys in the low-exposure group also reported increased feelings of sadness after playing the violent game.
Both groups of boys had higher stress and anxiety levels after playing the violent game, according to the study, which was published in the May issue of Psychosomatic Medicine: Journal of Biobehavioral Medicine.
"The violent game seems to have elicited more stress at bedtime in both groups, and it also seems as if the violent game in general caused some kind of exhaustion," wrote Malena Ivarsson, of the Stress Research Institute at Stockholm University in Sweden, and colleagues. "However, the exhaustion didn't seem to be of the kind that normally promotes good sleep, but rather as a stressful factor that can impair sleep quality."
The differences between the two groups' physical and mental responses suggest that frequent exposure to violent video games may have a desensitizing effect, the researchers said. The study, however, didn't prove a cause-and-effect relationship, and it's possible that boys with certain traits may be attracted to violent games, the researchers said.
The American Academy of Child & Adolescent Psychiatry has more about children and video games.