Longitudinal Effects of Violent Video Games on
Aggression in Japan and the United States
Craig A. Anderson, PhDa
, Akira Sakamoto, PhDb
, Douglas A. Gentile, PhDa,c
, Nobuko Ihori, MAb, Akiko Shibuya, MAd
, Shintaro Yukawa, PhDe
Mayumi Naito, PhDf
, Kumiko Kobayashi, MAb
Center for the Study of Violence, Department of Psychology, Iowa State University, Ames, Iowa;
bGraduate School of the Humanities and Sciences, Ochanomizu
University, Tokyo, Japan;
National Institute on Media and the Family, Minneapolis, Minnesota;
Institute for Media and CommunicationsResearch, Keio University, Tokyo,
Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba, Japan;
Faculty of Economics, Takasaki City University of Economics,Takasaki, Japan
The authors have indicated they have no ﬁnancial relationships relevant to this article to disclose.
What’s Known on This Subject
Experimental studies have shown that playing violentvideo games causes a short-term
increase in aggressive thoughts, feelings, and behavior. Cross-sectional studies show
positive correlations between habitual violent video game play and both mildand
severe forms of physical aggression.
What This Study Adds
We provide the ﬁrst test of longer-term violent video game effects on aggression crossculturally. The obtained longitudinal effects inAmerican and Japanese youth samples
conﬁrm that playing violent video games is a signiﬁcant causal risk factor for later
CONTEXT. Youth worldwide play violent video games manyhours per week. Previous
research suggests that such exposure can increase physical aggression.
OBJECTIVE. We tested whether high exposure to violent video games increases physical
aggression overtime in both high- (United States) and low- (Japan) violence cultures. We hypothesized that the amount of exposure to violent video games early in
a school year would predict changes in physical...