A very useful and extensive psychological study from the University of Rochester, claiming that "the enjoyment from playing computer games likely stems from the healthy pleasure of mastering a challenge rather than from a disturbing craving for carnage":
Initially, many games are perceived as being fun. Much of our work is focused on understanding when games reach to deeper levels of satisfaction that often sustain engagement over time, and to identify both the healthy and unhealthy aspects of that play.
Much of the debate about game violence has pitted the assumed commercial value of violence against social concern about the harm it may cause. Our study shows that the violence may not be the real value component, freeing developers to design away from violence while at the same time broadening their market.
And three cheers for that. I've had too many conversations with game-makers (particularly from my Scottish locus) who, when presented with a range of possible game motivations and scenarios that don't involve spectacular male violence in urban settings, shake their heads and say, "just don't see the game in that, Pat. You gotta see the game." I've always suspected that this was male geek laziness on the industry's part. Incidentally, this report is based on a sample set that was 85% male.
Immersyve have developed a psychometric methodology called PENS (Players' Experience of Need Satisfaction) - be good to hear from some core games researchers whether they rate this. In any case, this is a much needed research distinction for games makers (and those who agonise about games' impact): the "competence and autonomy" that players get out of their game-play does not necessitate conflict or war contexts. (Many thanks to International Hobo for the link).