Have to agree with Grinity's "who cares" - it's entirely possible your son could be happier on his own than with same-age "friends" he can barely communicate with. I didn't have many friends when I was 7, and never in my life had more than five people I would've invited to a birthday party. My mother used to cry over "how lonely I must have been" - took her until I was 23 to finally realize I was actually quite happy all that time.