I'm interested in an entirely different theory. Autism has risen by approx 600% in the last 20 years. You can account for prehaps a 100-200% increase due to diagnosis becomming easier to access, the range of ASD that is now being diagnosed and the fact that many people are more willing to get diagnosis for themselves or children.
So we are left with a huge unaccountable dramatic increase. I lean towards the theory of evolution of mind. That the autistic brain is one of a higher concience, a more highly evolved brain design. Yes many people may scorn me or argue that it's a disibility but i do believe the theory.
Could it be more that in earlier times there was less support for the autistic so they had a worse outlook and were less likely to keep whatever caused it in the gene pool (if it is genetic)?
Freude, schöner Götterfunken Tochter aus Elysium, Wir betreten feuertrunken, Himmlische, dein Heiligtum! Deine Zauber binden wieder Was die Mode streng geteilt; Alle Menschen werden Brüder, Wo dein sanfter Flügel weilt.