What's the science?
Whether or not playing violent video games increases aggression and other negative behaviors is a topic of continued debate. Previous studies showing increases in aggression, tested behavior immediately after playing video games, so the effects could be due to ‘priming’ (i.e. aggressive thoughts are more accessible for a short period of time). This week in Molecular Psychiatry, Kühn and colleagues tested behavior after video games were played for a longer period of time.
How did they do it?
They recruited 90 healthy adults. Participants were randomly assigned to be in a passive control group (did not play video games), to play a violent video game (Grand Theft Auto V), or to play a non-violent video game (Sims 3) as part of an active control group. Each group completed 208 assessments (including the Boss-Perry Aggression Questionnaire) on aggression, worldview, hostility, frustration, mood, impulsivity, pro-social behaviour, and other measures, before playing, after 2 months of playing (30 min/day minimum), and 2 months after they finished playing. The authors statistically analysed the findings using two types of statistics (Bayesian and Frequentist).
What did they find?
They assessed whether the pre-play scores and the post-play scores were different across groups (an interaction effect), and found no negative effects in the group that played violent video games. Specifically, only 3/208 statistical tests found negative (interaction) effects in the group that played violent video games post-play, but 10/208 tests would be expected to be statistically significant simply by chance, therefore, they concluded there were no negative effects.
What's the impact?
This is the most robust study to comprehensively assess the longitudinal effects of violent video games after long-term (two months) play. This study suggests that there is no evidence for long-term changes in behavior or aggression following violent video game play in adults, however, further research in children is needed.
S Kühn et al., Does playing violent video games cause aggression? A longitudinal intervention study. Molecular Psychiatry (2018). Access the original scientific publication here.