Could Cousin Marriages Fix Falling Fertility Rates?

Malcolm reveals statistics showing couples who are third or fourth cousins have more kids and grandkids than other couples. He and Simone discuss the evolutionary rationale for "cross-cousin" marriage in small tribes, as well as the downsides of first-cousin inbreeding.

They cover research on actual genetic risks, which are lower than commonly assumed. The Catholic Church banning cousin marriages out to 17th cousins is highlighted as a way they disrupted inheritances. Inter-ethnic marriage benefits are also touched on.

The conversation gets into Western culture's taboo and fetishization around incest, effects like the Westermarck Effect, and how repulsion/attraction can sometimes get reversed. They debate whether future advancement could eliminate risks that block sibling marriages.

Simone Collins: [00:00:00] Some hot,

Malcolm Collins: hot stats. Some hot stats. Simone, one of the things that people always tease us for when

Simone Collins: they're looking at pictures.

Oh, I had a good intro for this. Can I do an intro? You can do the intro.

Would you like to know more?

Simone Collins: So Malcolm, you know how like, basically since we, we started working together and doing things together, people assumed that we were brother and sister. And so at parties, when I, you know, was introducing myself and you to people and you were on the other side of the room and they, they, You know, you weren't in the conversation and I was trying to point out where you were.

I would, I just gave up and started saying, Oh, you know, he's the guy who looks like he's my brother. And I went immediately knew who you were.

Malcolm Collins: Oh yeah, and pictures online of us, whenever we go viral for this or that thing that we've done recently, one of the most common insults is, well, they look like they're a brother and sister.

Yeah. And It's funny because I think what they're actually seeing, because one of the things that we often point out is our sort of cultural slash ethnic group [00:01:00] used to be a very common ethnic group in this country and is now just a very, very rare one which is sort of the larger Calvinist cultural group and it's just not that common anymore and it what they're really noticing is just like, it's your first time meeting somebody who's like an Asian and they're weird and they're

Simone Collins: Asian.

Yeah, you look like you're related.

Malcolm Collins: Yeah, you look like you're related. Like, but if you go to like the town I'm from, because my family came from like a small offshoot of that group, but that had tons and tons of kids. So like every one of my family has over like three or four kids. And historically we go a few generations back.

What was it? 14 kids per generation?

Simone Collins: It's a lot. Yeah. They had a

Malcolm Collins: lot of kids, but yeah, if you go like rural area around Dallas, like everyone looks like me, you'll be like,

Simone Collins: even, even in Dallas, people look like they could be related to you. It's, it's a little bit creepy. Yeah.

Malcolm Collins: Just generic Texan. What makes somebody Texan?

But, but What I wanted to go into here on this [00:02:00] particular topic was a very interesting statistic I saw recently. Which brings up an interesting question, which is as pro natalist advocates, should we be promoting people marrying their cousins? Oh

Simone Collins: boy. Yeah. I mean, a very, some very, very high birthrate cultures do have

Malcolm Collins: a lot of, Simone, if you, I'm just going to give a quote here.

Okay. Okay. So this is a, a study that was done recently. It was couples who are third or fourth cousins tend to have more kids and more grandkids than other couples. The research. The researchers suggest marrying third and fourth cousins is so optimal for protection of have the, quote, best of both worlds, end quote.

While first cousin couples could have inbreeding problems, couples who are far removed from each other could have genetic incompatibilities. Mm. And if [00:03:00] you look the, the, the, the study, if people want to read the study on this it was called kissing cousins have more kids. It was published in 2008.

They went for it. Oh, no, wait, that was the name of the study. That was the name of the article on the study, I guess. Oh,

Simone Collins: oh man. I, I really love it when academics just like fully go for it with funny titles and that I'm disappointed.

Malcolm Collins: Yeah. And it makes. So there's, there's probably a few things at play here, right?

Okay. Okay. One thing I think they're, they are right. Which is you are going to have genetically healthier children, likely if you marry a third or fourth cousin than if you marry somebody completely unrelated to you. I mean,

Simone Collins: like, do you, is there, did you read in this any like clarity on like how much the, the.

Risk is reduced. Like if you're a third cousin, are you very, very unlikely to have genetic

Malcolm Collins: problems? So you may not know this, but the most common marriage type in the world. So this is, if you're talking not in terms of number, like for [00:04:00] example, if I say something like what is it? I think it's like 85 percent of all human cultures are polygynous, i.

e. it's one man, many wives is the norm for people who are wealthy within those cultures. I don't mean one. You know, that percent of people in the world, because the most successful cultures are obviously the monogamous ones. Now, when I say this, what I'm talking about is on a per culture basis. So most cultures, like if you're talking about the vast amount of cultural diversity, it's small cultural groups that like live in a rainforest somewhere.

Because, you know, like, The United States is largely like one or two cultural groups, right, where if you're talking about like one region of woods or something, you might have like a huge diversity of cultural groups. Well, if you divide cultures this way the vast majority of cultures prefer, no, not the vast majority, I think it's like two thirds prefer cross cousin marriages.

By count. By count. Yeah, by, well, percent, count, whatever you want to put it. Do they

Simone Collins: have, like, [00:05:00] by cousin, do they mean more removed cousins? Like, third, like, I'm just really concerned about Cross cousin

Malcolm Collins: means first cousin. First cousin marriages. So let's explain why they do this. See, that's This is So do you know why you would choose a cross cousin marriage?

A genetic reason why you would do this. If you're living in a small group of humans, this is for the audience too. Oh yes,

Simone Collins: yes. So the genetic reason for doing this in really small communities is it's the best way to make sure that you're not marrying someone even more closely related. Exactly. Like at least you're not, you know, marrying.

Malcolm Collins: They marry cross cousins because it reduces the rate of inbreeding rather than increases the rate of inbreeding, which is very counterintuitive to people. That is because you're cross cousin. So a cross cousin is the cousin of the opposite sex sibling to your parent. So let me, that takes a little explanation.

Simone Collins: Yeah, maybe give us some

Malcolm Collins: scenarios too. So a cross cousin would be my [00:06:00] mom's brother's kids or my dad's sister's kids. And the question is Why would