im very peaceful and gentle in real life, but i just played left 4 dead 2 for about 2 hours. and i started playing gory video games when i was like 6 (original doom anyone?) but yet grew up fine. and i know many other people who are the same. i dont condone someone playing video games when theyre under the age rating, but violence in video games and violence in real life are two very different things.
its like racing games. if you play racing games, will you be dangerous on the roads? most likely not.