Firstly I'm not even going to go on about the tons of the spelling mistakes you made. (The ones that make you look like 4 instead of 14.) But, secondly, and more importantly, It depends on the video game your playing. GTA, I have to agree with, is a very violent game. (I'm questioning why you let your 11 year old brother near it) But games like Minecraft, (Which has very little violence, no blood or gore, just a mob turning red and eventually turning into smoke, items and experience points, if you hit it enough, AND are more appropriate for your 11 year old sibling.) I have seen no proof of mentally unstable or violent people due to playing. Finally, as long as your more-mentally-mature-than-you brother keeps the "Shooting people in the head and shit like that" in the context of the game, It should be fine. If he actually says "I'm going to shoplift a Matbea 6 revolver and shoot the next person, in the head, that so much as looks at me the wrong way." Then you have a problem.