Meryl Horn

Yeah.

And that's sort of tricky to sort out.

Like, ideally, you'd look at identical twins, right, and expose one to acetaminophen in the womb and then see if there's like a difference in autism rates.

I guess.

I don't know how you would do that.

Yeah, exactly.

You can't do that.

But there is another way to get at this.

They could look at siblings in their data.

Yeah, that's great.

So Brian's team looked in their giant Swedish database and gathered thousands of cases like this.

They crunched the numbers and here's what they found.

No increased chance of autism.

Yeah, so what this means is that within a family, whether or not the mom took acetaminophen, the chance that her kid was autistic was the same.

So can you put this all together for me?

Okay, yes.

So the more I learned about this, the more I realized that there could be a completely different explanation for why acetaminophen and autism might seem like they're linked.

Because, like, if you imagine, like, say you're a mom of an autistic kid, that means that you're also more likely to be on the autism spectrum yourself, right?

You probably have some of these autism genes, too.

And being on the spectrum, having some autistic traits, that's actually been linked to having more pain when you're pregnant.