Hi, I'm not expert, but I'll tell you what I've seen, if it helps any. As a teacher, I can see a difference in the Asperger's kids vs the non-aperger's gifted kids. It's hard to put my finger on it exactly, but there is just something off. I've never worked with kids as young as your son, so I don't know what it looks like at that age. In older kids/teens, here's what I see:
They admire kids their age and follow them around, but really only "socialize" and "play" with younger kids. They seem really "normal" when they play with young kids, but never seem to fit in with kids their own age.
They are interested in specific topics and talk about those topics constantly. They seem clueless to the fact that everyone in the group is bored of that topic and they don't pick up on the subtle (and sometimes not so subtle) hints that everyone is getting annoyed with them.
They are physically awkward. Perhaps not clumsy, but they never seem to do as well in PE and sports.
They struggle with small talk and banter. They stand in the group and listen to the joking around, but if they contribute its usually something that doesn't quite fit. One example I saw just the other day: a group of 6th grade boys are being macho--playfully shoving each other's shoulders and making mild insults. They are basically nice boys and are trying to include the boy with Asperger's even though he he annoyed them earlier in the day by talking way too long about what he ate for breakfast. The boy with Asperger's does not really understand the unspoken boundaries; he shoves too hard and make a cutting insult rather than a playful insult. The other boys shout "Dude! What's your problem?!?" and leave. The Asperger's boy doesn't understand what went wrong.
Sometimes when I watch the Asperger's kids trying to fit in, I imagine tourists trying to fit in with a foreign culture. As tourists they've learned how to speak the language, but they don't understand the slang or the body languge. The natives are nice and include the tourists in their day to day life, but the tourists basically just follow the group around rather than truly belonging to the group. They might call these friendly natives their "friends" but there isn't a real connection there.
