ok, i'm done with this now.

so, what is autism?

it's a highly individualized random error in translation that prevents the expression of specific genes. no two autistic people have the same error (well, unless they're biological twins, which i'd guess is some kind of weird entanglement issue).

what causes it?

bad luck. but, anything that increases mutation rates, like exposure to pollutants, would in theory increase error rates, leading to higher autism rates. and, pollution would appear to be a major risk factor, which is something we can actually fix.

https://www.statnews.com/2018/11/19/pollution-pregnancy-autism-vancouver/