D.B.
Dear A.,
Gosh this sounds so familiar! I too had a quiet son w/different interests than the rest of his friends. He is now 21 and has a wonderful self-esteem w/awesome talents and abilities!
You have recieved some very good advice from all but I would like to second the advice from one about enrolling your son in a type of karate class if you can afford it. There are many to choose from in the area. When my son joined a karate class he learned many things from his instructors in addition to the self-defense lessons and confidence in himself. For example, they even had social nights and were given "lessons" on social circumstances. They roll-played situations which I believe would benefit your son. I believe having these lessons taught from others he looked up to, in addition to all the instruction I had given him on these subjects was a win-win.
Though he didn't express interest when we first enrolled him he actually enjoyed it as time went on.
I believe enrolling him in karate was one of the best things we did for our son at the time.
Good Luck!!
D. B