Read the most advanced science of autism causes here. Bypass the commenterati and go direct to the science. Don't waste your time at the sites which pretend "no-one" knows what causes (or what sometimes cures) autism.
This is a website relating to the unchallenged theory of autism, IQ and genius, Personality and Individual Differences 14:459-482 (1993) by Robin P Clarke (the antiinnatia theory). An update review paper is being prepared for publication. Meanwhile you can download the original 1993 publication (presentationally revised) here, and the original 1993 publication (author's reprint) here . (the journal site version is here:, but without added charts of social class and you may have to pay Elsevier $31.)

Good review of autism increase question

A notable review of the debate on whether or not autism has increased can be found here. Interestingly, it leads to the same conclusion as myself - that the increase was real - even though not raising what I would consider the trump card fact presented in my update review. But then, no one else besides myself has noticed that point yet.