Not quoting because it's slowing up my computer. But you can prove these things statistically and they mostly have been proven. The only problem some people have is that other people are fine using correlations without causation that don't control for a number of other of factors to rig expierments to make it look a different way. The reason for this of course is that they get paid a lot to do so.
With a degree in something like psychology, sociology or any sort of expieremental science it's fairly easy to pick apart good studies from bad ones.
If violent games are like other "vice" products if anything they lower the things they are claimed to increase.
After all, that "virtual" person is the perverbial "kicked dog" for some people. The advantage in the game however is that this dog does not feel it as opposed to if your kid takes out his stress on a real pet.
