Ill chime in because my daughter is like this and my son is the complete opposite. I do agree it could be many things or it could be nothing. The most important thing is that your son is not depressed and is fine with his lack of social life as others mentioned. Theres not much you can do otherwise Im learning, but to be supportive, keep offering social activities with the family at least, be patient, and try to learn about what he likes. Everything is the same that the others mentioned already, its hard to see our kids like this, but things might be just fine. I will always want more for my kids too, and for them, they may feel they do have all they want or need. I just wanted to let you know I understand.