There's also a correlation between mothers who breathe air while pregnant and children who develop autism. And sometimes even children who don't!

An article from last April in JAMA also compared between a no-control cohort and a sibling-control cohort. When a control is there for comparison, the potential correlation goes away meaning it's just as likely any findings are confounded anyway.

That was shit, underpowered science that should never have been funded or published. A proper Swedish study of 2.5 million proves, without a doubt, no correlation.

Granting agencies and universities need to get their shit together and teach epidemiologists how to do proper science because at this point, it's pretty close to psychology.

There is a correlation between mothers who take tylenol while pregnant and children who develop autism in some studies.

All people with autism, also had mothers who consumed water during their pregnancy... Did water cause autism?

But it could be just as likely that autism is both hereditary

At this point, it's almost a certainty that this is the case, possibly activated by environmental influences during pregnancy. However, none of the influences have been identified, as there's (Last I looked) about 30 separate DNA sequences that are related to autism in people.

For what it's worth... there's about the same number of DNA sequences involved in someone requiring corrective lenses.