This is one of the reasons why we initially doubted the AS dx --we've not seen him as inflexible, at least when we look at lists of behaviors for AS like the one above. He's had a total of two tantrums in his eight years, and that's including the toddler years. He's very go-with-the-flow and he doesn't protest to anything. He will offer his opinion, but then he lets it go without a fuss. Could it be that he's just exhibiting differently than many AS kids? (Like I would know what's normal!)
There is a wide range of what counts as AS, and nearly nobody has all the possible symptoms. In Sohn and Grayson's book Parenting Your Asperger Child they go through a list of types... possibly yours is a dreamier type, rather than a more explosive type.
The difficulty connecting with peers is a key component no matter what type.
He just says, "I seem to have a big problem with focusing. I don't know why I can't _____." It doesn't seem to matter how many times we talk about it or walk through it, he just isn't "aware" in the moment if he's zipping around in play.
It can sometimes be like their radar is tuned to things but not people. Though my DS is very social... just not good at reading cues.
Okay, I guess I'm back to "just take him to a doctor." Any suggestions for the 'type' of doctor?
Who diagnosed the AS? Is he receiving any services now?
I'd say, take him to a neuropsychologist. (Ours works in tandem with a developmental pediatrician, which is great.) They can do a wide variety of tests to figure out what's going on. My feeling is, it's important to have good diagnostic information; at that point you can then use that information to formulate a plan to improve things and work on the missing skills.
DeeDee