Exposure to violent video games makes children more aggressive and less caring, regardless of their age, sex or culture, says a new study.
"We can now say with utmost confidence that regardless of research method -- that is experimental, correlational, or longitudinal -- and regardless of the cultures tested in this study (East and West), you get the same effects," said Craig Anderson.
Anderson, who is director of Iowa State University (ISU) Centre for the Study of Violence, led the study, based on an analysis of 130 research reports on more than 130,000 subjects worldwide.
"And the effects are that exposure to violent video games increases the likelihood of aggressive behaviour in both short-term and long-term contexts," said Anderson.
"Such exposure also increases aggressive thinking and aggressive affect, and decreases pro-social behaviour."
The study was conducted by a team of eight researchers, including ISU psychology graduate students Edward Swing and Muniba Saleem; and Brad Bushman, a former ISU psychology professor who now is on the faculty at the University of Michigan.
Also on the team were the top video game researchers from Japan - Akiko Shibuya from Keio University and Nobuko Ihori from Ochanomizu University - and Hannah Rothstein, a noted scholar on meta-analytic review from the City University of New York.
The team used meta-analytic procedures - the statistical methods used to analyse and combine results from previous, related literature - to test the effects of violent video game play on the behaviours, thoughts and feelings of the individuals, ranging from elementary school-aged children to college undergraduates.
The research also included new longitudinal data which provided further confirmation that playing violent video games is a causal risk factor for long-term harmful outcomes.
The analysis found that violent video game effects are significant in both Eastern and Western cultures, in males and females, and in all age groups, said an ISU release.
The study was published in the March issue of the Psychological Bulletin, an American Psychological Association journal.