jewishfeminist02: I agree, a child of seven shouldnt be playing a wrestling game. But give him a sport, puzzle or adventure game and thats time well spent.
As for statistics: http://arstechnica.com/news.ars/post/20050815-5205.html
And this is also interesting reading on the subject: http://culturalpolicy.uchicago.edu/conf2001/papers/goldstein.html