Kyle Harper

And what's happened is really two things.

One is

There's more energy per capita.

So people eat more.

They eat more calories and they eat better calories.

They eat lots of bad stuff too.

But like people eat more.

And two, the burden of infectious disease has been lowered.

And growth, the growth for a human is a very complicated trait that's influenced by genetics.

So I was never destined to be –

You know, super tall.

But it's also affected by environment, which includes, but it's not limited to, what you put in, nutrition, and then what you spend either doing labor or what you spend fighting infectious disease.

Infectious disease imposes a huge burden on the body.

the immune system is extremely metabolically expensive.

And so if your childhood is spent just fighting infectious diseases, you're going to struggle to invest energy and growth.

So there's a massive increase in the size of populations over the last 250 years.

And even though it's an even more complicated trait,

This improves people's cognitive abilities.

People are smarter.

Like, may not feel like it.