This is an interesting look at violence in games and social or behavioural carry-over.
A synopsis for those uninterested in the entire segment: In a one- or two-year study of 1250 children from across the U.S., Harvard researchers found a behavioural pattern amongst both boys and girls: Those who did not play violent video games were/are more likely to have real-life behavioural issues and manifest violence against others. The other extreme that applies to boys only is that those who played violent or mature games for more than 15 hours a week also displayed similar behavioural dispositions.
Now that's interesting. Playing violent or mature games actually leading to reduced risk of social violence?
Given the amount of research (and/or opinion) on the other side of the fence, viz. that violent games cause and reinforce unhealthy and harmful behaviours, I expect both the book and its study results to come under a great deal of fire.
On this same topic, I read an article a few weeks ago. It discussed research done on brain patterns of video game players. To paraphrase, it found that stress levels and aggression receded while playing violent games, especially online games that focused on fighting real people over the net. I'll try to track that down and post it here, or in another post. It also talked about stress and anxiety levels of merely wounding another player in game vs killing them. Anxiety and fear brain responses were triggered in situations where the player did not outright kill or otherwise remove an enemy player. Killing or removing them caused a healthy release of *insert medical term I can't remember here*, promoting bodily health.
Terra Nova is a "collobarative weblog featuring several important scholars in the field. General focus is MMORPGs and social aspects of online gaming communities." It tends to deals with MMO-style game influences, lessons learned, how to apply virtual theory to real-world situations, etc. I haven't read much of it because it tends to deal mainly with Second Life and EVE:Online, neither of which I have any interest in. However, the articles make for interesting reading given the prominence in the field of the authors.