As this topic has unintentionally touched off a bit of a firestorm, let me post a few things.
First, I have noticed that the efficacy of a diagnosis is directly proportional to the diagnostician's proximity to the patient. There being an uncalculable amount of ether between all of us here in these internets, a diagnosis from afar runs great risk. That a lengthy follow-up post clarifying an earlier post was necessary, I think, makes my point.
My son is not an only child: he is the oldest child. He is no more sheltered than most other near-twelve year olds that have come face-to-face with his own mortality: he's been through three major surgeries in his short life. His IQ, as measured by professionals at the University of Louisville, is 128. He is consistently on the A-B honor roll at an educationally rigorous private school.
He has been diagnosed with Asperger's syndrome. Among other ways it affects him, Asperger's has slowed his maturation relative to his peers as a whole, and especially measured against his female classmates in these late, pre-teen years when girls naturally tend to outpace boys. This manifests itself in the classroom and is a constant struggle for him and his teachers. He works hard at recognizing these limitations.
I don't believe he is sufficiently self-aware to realize that his classmates have already discovered that Santa Claus is not real. Instead, I suspect that he clings to Santa as part and parcel of the whole magic of Christmas. In his mind, Santa is the ship that keeps all of Christmas afloat. I, personally, am not prepared to torpedo that belief.
Did I lie to him when he asked if Santa is real? You bet and I'd do it again today and tomorrow if need be. I think it would have been different had I refuted a declaratory statement --'Dad, I know Santa isn't real' -- as opposed to answering the question of someone that still wants to believe. Whatever the case, I think all parents have to recognize the context from which the lie springs: namely, of having put this myth (and others) before our children in the first place, nurturing it for years, and then going to extraordinary lengths to perpetuate it.
I don't know any adults that still believe in Santa, or the Tooth Fairy, or the Easter Bunny. He will, sooner rather than later, I suspect, make that statement to me -- that he knows Santa isn't real and of course I'll tell him he's right.
Then I'll tell him if he spoils it for his little sister, I'll knock him into the middle of next week...