I have been considering this a lot to understand myself. Sorry about 'high functioning' terminology but I wanted to differentiate and I can't talk about anything I don't have experience of.
I have come to the conclusion that high functioning ASD is fundamentally an overly sensitive nervous system, which causes mode changes in the brain and inhibits social development, because people are unpredictable and a threat?
The sensitivity to over active nervous states drives confusion and mal-adapted coping mechanisms.