My son (5) broke his arm on holiday and didn't cry once.
When he was younger he shut his finger in a door and the finger nail went back - didn't flinch.
He has only screamed in night terrors so I don't count that as crying and sobbing.
He didn't even 'properly' cry (I mean like my daughter)when he was a baby.
He had terrible tonsilitus before he had them out - never cried or appeared distressed at being ill (apart from having a temperature). Also when he has had stomach upsets he just gets up, is sick and goes back to bed or goes back to what he was doing - no distress as such.
I guess what I am asking is do children with AS have higher pain thresholds?