He is aggressive. Everything he does is loud, aggressive, and impulsive. Fortunately, he seems to be intelligent, so he may have the mental tools to override his impulses if he gets the right guidance (which may be unlikely, as his family are happily statist).
I realize that some of that is "just being a boy" (I was never that way), and he'll undoubtedly grow out of a lot of it, but will a person like this be less likely to accept the Zero Aggression Principle, or, even if he acknowledges it, be unable to abide by it? How will people like him fare in a free society?
And what about those who are like him, but not intelligent? I hate to think that anyone is just doomed before they ever get a chance, but on the other hand, everyone, smart or stupid, has to live with consequences. That's just reality, and isn't something you or I can prevent.