Razib Khan - Genomics, Intelligence, and The Church of Science

**Dwarkesh Patel** (0:05)
All right, today, the pleasure of speaking with Razib Khan. He's one of the top science bloggers in the world. He writes about genetics, history, and evolution on his blog, Unsupervised Learnings, and he has a podcast of the same name.
And you can find it at razib.substack.com. So Razib, thanks for coming on the podcast.

**Razib Khan** (0:23)
That was my pleasure, man.

**Dwarkesh Patel** (0:25)
Yeah, yeah, so can you give my audience a little bit of background about you, how you got into all this stuff?

**Razib Khan** (0:30)
Yeah, you know, I've always been interested in topics like history, demographics, et cetera. And I've also been interested in science, have a scientific background, scientific training. And over the last 20 years, genetics has become just a really big deal in terms of, you know, just as a tool to do various things, whether it's in the biomedical space or historical inference. And, you know, so obviously I'm interested in demographics, historical inference, and, you know, genetics is a tool I can use as a geneticist, and so I do.
So, you know, like, as we're recording right now, I decided to do a bunch of pairwise genetic distances between populations and stuff, just because I could for a post, you know? So, you know, I do a lot of things by myself, while I replicate what's been done. Yeah, so, I mean, that's a lot of what I do, yeah.

**Dwarkesh Patel** (1:33)
Okay, interesting.
All right, so I just like to jump into it. So, my first question is, assuming there's no gene editing in the near future, what is the long-term equilibrium for intelligence look like? So, there's, like, multiple visions, right? Like, one view is, like, you know, Charles Murray coming apart. You have, you know, you have fat tails because there's assortative mating. Another is there's, like, a slight disgenic effect because there's lower fertility among higher intelligence people. So, what does the equilibrium look like if there's no gene editing?

**Razib Khan** (2:04)
More like the second, in terms of not an equilibrium yet. We're not going to have an equilibrium until, you know, the reproductive referentials equilibrate. They will at some point, you know, but it could be centuries.
So, like, at this point, people with genes for educational attainment tend to delay childbearing to the point where a lot of them do not have children, you know, because they invest in educational attainment in the short term. So, you know, they don't have as many children and their generation times are longer. Like, the math is difficult there, right?
So, right now, there's a strong negative selection. Not strong, there's a negative selection on genes for educational attainment. I mean, everyone who's looked at it says that, at least in the developed world.

**Dwarkesh Patel** (2:50)
Right. Is this something we can expect in the long term? Because, like, naively, I would expect, like, people who are more intelligent, as long as there's, you know, some sort of selection pressure in the long term, you know, like, there should be selection for, I guess, educated, smart people because they will just have the cognitive tools to, you know, actually reproduce or, you know, survive and thrive, right?
As long as, like, some smart people want to survive and thrive.

**Razib Khan** (3:20)
Yeah, I mean, you know, survive and thrive is one thing, but have a reaper, have reaper, have offspring is a different thing.
You know, the incentives in our society are such that a lot of people believe that thriving is being child-free or, you know, what usually happens, I think, is people want to establish themselves in their 20s and they don't want to put too many, too much thought. I mean, at least, you know, professional managerial, you know, college-educated people.
And then in their 30s, they start thinking about it. And sometimes people wait too long. There's fertility issues or they just wait too long. They can't find someone else, you know. So, yeah, in the long term, obviously, there's a limit. There's limiting principle, but you don't need to be that bright to, you know, survive and have a lot of children. And on the contrary, there's clear evidence that not being bright is good for your reproductive output. So, you know, the movie about that in 2006

**Dwarkesh Patel** (4:18)
The movie is called 2006?

**Razib Khan** (4:21)
No, 2006, Idiocracy.

**Dwarkesh Patel** (4:23)
Oh, I see.
What explains the level of endogamy you see between Indian Jatis, like Indian subcasts? Because you have a very excellent blog post about this. And apparently, as you say, there's genetic evidence that for thousands of years, these Jatis living in the same village, they're not intermarrying, they're not having kids together.