Now game violence effect discussion is active again in Sweden after Karolinska Institute researchers have been publishing their opinions in DN, I did some research on the topic (again).
A report Understanding the Effects of Violent Video Games on Violent Crime by Cunningham et al (2011) states:
First, they [the study results] support the behavioral effects as in the psychological studies. Second, they suggest a larger voluntary incapacitation effect in which playing either violent or non-violent games decrease crimes. Overall, violent video games lead to decreases in violent crime. (http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1804959)
I previously posted about a review study that links personality traits and video game violence influence, but the authors posists following reservation:
Given the number of youths who regularly engage in VVG play and the general concern regarding this media, it would seem likely that resulting violent episodes would be a regular occurrence. And yet, daily reports of mass violence are not reported. It appears that the vast majority of individuals exposed to VVGs do not become violent in the “real world.
US Supreme court takes very similar stance that the two above studies:
Psychological studies purporting to show a connection between exposure to violent video games and harmful effects on children do not prove that such exposure causes minors to act aggressively. Any demonstrated effects are both small and indistinguishable from effects produced by other media.(http://www.supremecourt.gov/opinions/10pdf/08-1448.pdf)
Games Briefs has an interesting figure on the topic (video game sales vs violent crimes / US figures). These figures are also in the line what said in above.
While there is definitely need for research in the area (as well as restriction for selling games for minors), it should be obvious that the effects of playing are not very straightforward. If they are, we would be seeing rabidly raising amount of violent crimes even with small effect sizes.
Gerald Jones have a good critical take on subject in his book Killing Monsters! Why Children Need Fantasy, Super Heroes, and Make-Believe Violence were he argues that make-believe violence has a role in children development.
EDIT:
There is also methodological issues in effect studies conducted to children (from the Gerald Jones’s book; I do not have book now, so no pages numbers.).
- The test setup can be cause of aggression itself
- Make-believe (playing about what was just seen) is interpret as aggression.
EDIT2:
Gerald Jones discusses the issue on media effect studies on pages 23-44 (Killing Mosters).
EDIT3
Links to the discussion in DN (in Swedish, not exhaustive)
Economist version of the graph showing raise in videogames sales and decline in violent crimes: http://www.economist.com/node/21541166