David Reich

So, you know, this is the power of data, right?

Like, you know, the...

I think Joe, if you asked him prior to this work what the hunter-gatherer selection would be and where their set point for this particular trait would have been, I think he probably wouldn't have made a very strong prediction, but he would have said, well, maybe you would have expected it to have a high predicted value of this trait because these people were really having to do a lot of things and figure a lot of stuff out, maybe.

And that maybe once you have more complex societies, there'll be more of a collective brain and

Maybe there'll be selection against this trait.

And in fact, it's sort of the opposite in some ways.

So it's the power of data.

It's not what you expect.

And after looking at this data, it's actually the value of data to try to make sense of all these things.

It's very interesting, like the genetic predictor of intelligence, there's lots of kind of things that are confusing about it.

So it's actually worth talking about it.

Or the genetic predictor of years of schooling, which is highly correlated to it and is measured even better.

Yeah.

So if you look at the genetic predictor of years of schooling, there's another amazing study from 2017 from a group in Iceland that looked at this measure over the last hundred years in Iceland.

And it looked at older people and it looked at younger people, people born more recently in Iceland.

And there's an estimated 0.1 standard deviation decrease in genetic predictor of intelligence in Iceland just within one century.

It's an absolutely huge effect over a short period.

And this is selection against years of schooling.

If I said intelligence, I didn't mean to.

It's selection against the genetic predictors of numbers of years of school.