I couldn't wait to move out, but that fact that you're here shows that you're more understanding than my parents are. If he goes to a large university there is a better chance that there will be a larger group of people he will fit in with. There's a better chance that there will be some sort of student organization related to his special interest(s), another excellent place to make friends. One thing I like about college is that I can choose to be alone when I want to, that's an important component of stress management for me. For me, when I'm unstressed I'm more capable of more in-depth interactions with others. So maybe if he gets his quota of alone time, he'll be more likely to go out and make friends. If you aren't concerned about his academic ability or his ability to take care of himself, I would let the social aspect take care of itself.