Results from a recent meta-analysis did not support the conclusion that violent video game playing leads to aggressive behavior. However it was associated with higher visuospatial cognition such as visual rotation, visual memory, visual attention and selection or related abilities.
These findings are valuable since it is not hard to link video game playing to aggression because the prevalence of video game playing in adolescents is 98.7%. In contrast excess violent behavior such as a school shooting has a very low base rate.
Can an almost universal behavior truly predict a rare behavior? According to this excellent meta-analysis: No.
Shortcomings of previous trials and reviews:
1. In one study the confidence interval crosses zero, so instead of proof of a relationship this publication questions such a relationship.
2. Violent activity may simply be a byproduct of family violence.
3. Use of unstandardized measures of aggression
4. The assumption that these games have only negative consequences could be wrong, positive aspects are neglected.
5. Publication bias
When correcting for this publication bias the result of the meta-analysis does not support a relationship between violent video game playing and aggressive behavior.
A total of 17 published studies comprising of 21 independent observations were found that met the above criteria including a total sample size of 3,602.
When correcting for the publication bias, violent video game playing does improve visuospatial cognition.
A total of seven published studies comprising of 14 independent observations were found that met the above criteria including a total sample size of 384.
The author suggests to look into the effect of violent video games on individuals already at risk for violent behavior. He also suggests to look at adopting these games for more positive goals e.g. educational purposes.
Psychiatr Q. 2007 Dec;78(4):309-16.