Well, kids are by definition self centered, cruel, violent, and have self control issues. This is why parenting is such a big deal. Children are not "little adults" or simply uneducated, they are fundementally differant as they have not fully developed in an
emotional and intellectual sense. For some reason people like to think children are some kind of blank slate, or inherantly passive, that's hardly the case. Children are very much driven by insticts, in a pure, and fairly animal form, with their own needs before anything else. This is why it can take quite a bit to reinforce behaviors like sharing and communal action.
If you look at some of the things children have done throughout less civilized portions of the world, including becoming soldiers, or even warlords in their own right, not to mention hardened gang bangers one famous example: http://en.wikipedia.org/wiki/Robert_%22Yummy%22_Sandifer ... and remember "Yummy" was before the current video game "problems" in the media.
This is to say nothing of books like "Lord Of The Flies" and Steven King's "Children Of The Corn" which are famous shockers because they get right down to the basics of this reality.
At any rate, I think the problem here is that the researchers are disturbed when they find the children don't match the tendencies they have mentally created for them. Forgetting about the fact that kids, especially boys, have been running around shooting each other with toy guns and fighting with toy swords pretty much forever, video games are just a fancier way of doing the same basic things.
Older groups being "less affected" is more a matter of them just being more mature in general.
Now granted, I *DO* think that violent video games and such should be kept away from children, and I see that as part of parenting. I do not however believe that keeping kids away from violence is a good idea, and quite counter productive, because face it... that's how kids play. You just have to watch out to step in to prevent (and punish if need be) actual fighting.
To be honest though, I'll be frank in saying that the biggest reason for keeping kids away from a lot of this material is *NOT* for fear that it will turn them into a psycho-killer or anything. It's because kids are easily frightened, and the big reason why you keep kids away from things like horror movies, and ultra-violence, is because you want to get some sleep. You show a kid "Nightmare On Elm Street" the issue isn't that he's going to want to be Freddy, the issue is that he's not going to want to go to sleep because he's afraid Freddy
is going to get him if he does. Since you have to go to work, and he has to go to school... well the problems here are obvious.
To be honest, most of the action heroes in video games today are not really all that differant from the ones of yesterday. Entire generations grew up with guys like John Wayne and Clint Eastwood before all this current contreversy. Seeing a bunch of military guys or cops wipe out bad guys today, is no differant than seeing it in the older movies. Sit down and actually watch some of those old Westerns and stuff, a lot of them are pretty brutal. They also use a lot of the same exact ethics and conventions you see in current action fare. The Sheriff heads out alone (or maybe with his Deputy) and takes out a bunch of outlaws, is really very similar to a police officer (and maybe his partner) taking out a bunch of organized crime people.
