Yes, that makes sense about the correlation.
I suspect, though, that autism is a spiritually-inflicted mental illness.
That is to say that God arranges that the circumstances are such that
the offspring become autistic.
I might add that it is a terrible cross to bear, for my best friend from high school
had twins and the girl is autistic. The trials that my former friend described sounded
horrendous.
The boy is at Yale [or may have graduated by now] and is really brilliant.
The girl of the pair was terribly afflicted : unable to do anything for herself.
So I believe it may be about the particular soul - OR something to do with belief in God
and so many factors that none but God would know.
To sum up, I think that external factors are not the most crucial ones, but
spiritual factors hold the hidden reason why this tragic condition appears
PS - my friend and her husband helped originate a new approach to the care of
autistic adults who have to leave the family nest. If anyone is interested,
send me a PM and I can give information about that very successful new project.
I wouldn't put it here publicly, of course, to protect the family's privacy.