Twentieth-century cousin marriage rates explain more than 50 percent of variation in democracy across countries today.

That is the last sentence of the abstract in this job market paper, from Jonathan F. Schulz:

Political institutions vary widely around the world, yet the origin of this variation is not well understood. This study tests the hypothesis that the Catholic Church’s medieval marriage policies dissolved extended kin networks and thereby fostered inclusive institutions. In a difference-in-difference setting, I demonstrate that exposure to the Church predicts the formation of inclusive, self-governed commune cities before the year 1500CE. Moreover, within medieval Christian Europe,stricter regional and temporal cousin marriage prohibitions are likewise positively associated with communes. Strengthening this finding, I show that longer Church exposure predicts lower cousin marriage rates; in turn, lower cousin marriage rates predict higher civicness and more inclusive institutions today. These associations hold at the regional, ethnicity and country level. Twentieth-century cousin marriage rates explain more than 50 percent of variation in democracy across countries today.

Here is Jonathan’s (co-authored) working paper on “The origins of WEIRD psychology.


While Francis Fukayama made a similar point about the Catholic church facilitating national building in the medieval age, arguably marrying your cousin is simply a function of how 'closed' your village is; if you can't move around a lot, you end up marrying some version of your blood relative. That's how the Balkans work (everybody in my Greek parents little village is somehow related). Incest is the idiot? See the bonus trivia below!

Bonus trivia: if you marry even your first cousin, your chances of siring a retard goes up, but not to like 80%, it's like from 0.3% to 1.5%. Even two related, retarded people marrying and having kids (which I've seen in my village in Greece) will produce healthy kids 75% of the time. Google "three generations of imbeciles is enough" a phrase Sup. Ct. Justice Holmes came up with (who was impotent due to a war wound in the neck, very common symptom, as is former PH president N. Aquino from an assassination attempt, from somebody I believe related to him by blood or marriage).

In South Carolina one may marry one's first cousin, and many do. I suppose that explains a lot.

It only explains the 1.5%, see above. But it's like the old joke that in a French assembly a feminist politician got up to say "DNA proves there's only a 1.5% difference between a man and a woman", to which the sexist rest of the assembly rose to their feet and simultaneously shouted "viva the 1.5%!" (nowadays they would shout "Vive le 1%!")

Don’t know if you are just being funny but cousin marriage rates in sc are obviously minuscule.


OK! So what you are saying is that marrying cousins produces more retarded children AND more Democrats???

You can marry your first cousin in California, but not in Idaho. That may explain things.

Comparing ancient to modern Greece suggests that the effects become unmistakable over time.

Its not just movement tho. The catholic church banned cousin marriage to a severe extent. At some times and places it was illegal to marry your sixth cousin even.

And of course you can contrast this with places that didnt ban cousin marriage, gained the technological infrastructure to move around a lot, and _still_ did not become a democracy (the entire non-western world).

Missed me!

If you say so - history does not have a point, it merely exists as a record of the past.

Though true, it is so much easier to make a point by ignoring history.

I suspect that this is a sensible thing to weight by population of those states, rather than use regressions in which India matters exactly a quarter as much as Denmark, Iceland, Sweden and Norway.

Particularly as a certain diversity chick points out that Protestant Scandinavia - with the exception of the Swedish Lutheran church for a century of so - permitted cousin marriage, in contrast to Catholic Europe.

In other words, those countries do not even represent the larger population of Catholic Spain or France, neither country particularly noted for 'higher civicness and more inclusive institutions today' compared to Scandinavia.

Though according to that same chick, in Alsace-Lorraine, it was the Protestants with lower cousin marriage rates than their Catholic neighbors - and both were under the Swedish percentage in the mid-19th century.

And the data from "inbreeding in Sweden" post of that diversity chick does show that Swedes didn't marry with their first cousin after the 1500s (and presumably before, since that Protestant ban might be a continuation of the earlier Catholic practice)

How much do the ethnically-Swedes drive up that civicness all across Scandinavia? How much do the non-ethnically Euro drive down that civicness in France? And Catholic Spain was split in two by the line of cousin-marriage.

'that Swedes didn't marry with their first cousin after the 1500s '

Well, until after the 1700s, that is - 'Thereafter, the prevalence increased nationally to an estimated 0.2% in 1750, 1.0% in 1800 and 1.5% by the mid-19th century.'


I am not sure that the Scandinavians consider themselves 'ethnically' different to any significant degree (culturally being a somewhat different aspect), and definitely not on the basis of there being a race of Danes, a race of Norwegians, etc.

Whenever I hear Alsace-Lorraine in the same topic as nation-building, I twitch.

I could totally believe that some of my present globalist tendencies hearken back to my Alsatian ancestry.

Catholic Europe also allowed cousin marriage with a dispensation from the Church. Among royalty uncle-niece marriages occasionally happened as late as the 19th century.

'I demonstrate that exposure to the Church predicts the formation of inclusive, self-governed commune cities before the year 1500CE': England, Scotland, and Ireland must be outliers then. Unless you care to class the City of London as being in that category.

May I take it that they gave copious credit to the HBDchick blog for promoting the hypothesis they tested?

Probably not, because she is pretty clear that in regards to Scandinavia, the hypothesis is not really possible to particularly support, to a large extent due to a lack of any records before the Scandinavians became Christians, some time after 1000CE.

I suspect your "probably not" is pretty plausible but your "because" is perhaps too generous.

>> 'I show that longer Church exposure predicts lower cousin marriage rates; in turn, lower cousin marriage rates predict higher civicness and more inclusive institutions today.'

> Well, the Scandinavians will likely be fascinated to hear that, considering that the complete lack of marriage records before they became Christians around 1000CE makes such a conclusion basically impossible to support.

There are two parts, A predicts B, B predicts C. Even if in part of your sample you have nothing on A, just B and C, you can still talk about A’s influence on B, and B’s influence on C.

Given our current reliance on pedigrees you’re right that comparing inbreeding in the Nordic countries pre and post Christianisation is impossible. Once they start genotyping every skeleton an archaeologist trips over they’ll be able to compare rates of inbreeding over time even without any written records.

Yeah... without having read this, I'm going with "this paper did not control for confounders very well". I guess his hypothesis would explain why all those Catholic countries have history of thriving democracy... oh wait... I'm sorry... I see those countries actually have a history of thriving dictatorship... there we go... I corrected it for him.

If your variable can predict the probability of having had a dictatorship (which I bet this one can) while also suggesting that it explains democracy uptake, then your hypothesis is BS.

Democracy is a modern fetish. It is perfectly possible to have a thriving culture without it. Humanity got along without it for millenia, and the universal franchise is even more recent. Do you think the charter cities that the billionaires will start forming are going to be democratic?

I'd say the top three social phenomena to avoid for thriving society are Islam, polygamy and cousin-marriage.

"Penicillin is a modern fetish. It is perfectly possible to have a thriving culture without it. Humanity got along without it for millenia,"

Just sayin'. But I agree on your top 3.

Democratic rule had nothing to do with penicillin. Numerous technological advances have been made in monarchical states. I'd submit that democracy actually leads to stagnation as a growing net consumer class votes itself benefits.

Yeah you submit a lot of things. Also way to miss the point.

A growing net consumer class that votes itself more wealth = a fairly nice problem to have!.... compared to an aristocratic or mandarin class that simply grants itself greater and greater shares of skim or the kind of low growth and productivity and periodic civil war and destruction of what little growth exist, the conditions bedeviling all autocracies and oligarchies known.

But a wealthy "drone" class of useless aristocrats is also a resource sink.

We've replaced useless aristocrats with useless bureaucrats. Democracy is loaded with perverse incentives. That's why charter cities won't be democratic.

Political institutions vary widely around the world, yet the origin of this variation is not well understood.

Substitute "clothing", "music", "religion", "literature", "art", "culinary practices", etc. for "political institutions".

, I demonstrate that exposure to the Church predicts the formation of inclusive, self-governed commune cities before the year 1500CE

So it's also responsible for socialism them?

No seriously, the Catholic Church actually was trying to create something like socialism when it did that. Those are the basic ideas underlying Chrstianity - to eliminate distinctions between rich and poor and create a single community - one giant family in which we are all brothers and sisters. That's kind of the goal of Islam too.

The protestant reformation seems to have been something of a freak accident where it put this spin on it that not only are we all equal, but were also totally autonomous - nobody can be compelled to particiate in the Church (and likewise any centrally planned project).

Christianity relies more on charity and treating people as equals, not socialist forced equalization.

For a very long time the Church was a quasi-governmental entity in it's own right and could compel tithes and membership.

During this time, church bishops were appointed by the local kings, and not by Rome. So it's not like the church was ruling Europe.

My point is that the Church was funded by a compulsory revenue steam. Its good works were not voluntary charity. They were more akin to a state provided safety net.

HBD Chick was right!

I haven't really read HBD Chick, but there is a difference between saying the church destroyed cultural institutions and saying it changed the genetics of the population.

If they changed cousin marriage rates then they changed the genetics of the population

I mean in the sense of "they eliminated those clannish genes and replaced them with liberal democracy genes". I'm sure that the Church's policy did reduce the rate at which recessive genes recombined due to inbreeding, I just don't think they bred a new variety of humans that aren't predisposed to kin-based tribalism.

The clannish genes would have a lower (perhaps negative) payoff in the new environment.

Changing selection changes genes.

As if, hes not saying "culture" while meaning "genes" in order to avoid getting in trouble. As if they arent practically interchangeable.

Considering the author works in a subfield called cultural evolution, I think he would very much believe that they are not interchangeable. Whether or not, you believe that they are interchangable or that the whole subfield is a cover for 'HBD' ideas, that's another question.

If culture is totally genetically determined then how come America isn't a feudal monarchy ?

The answer that is proposed to this question is that the Americans of the twenty first century are different than their tenth century forebears, the genetic changes necessary to transition a government being subtle enough to be done in less than 30 generations of selection and some shift in reproductive patterns.

Not wholly persuasive I think, but neither is its opposite counterpart; that we can be certain that 21st century Americans have the exact same psychological and cognitive genetics as the 10th centurians, or that if they do not it is irrevelent to their institutions and form of government.

Regarding the US, I'd say the legal of cousin marriage is far less salient than its prevalence: very low in most American communities, regardless of legal status.

Unable (yet) to access the paper, so can someone summarize how the RCC found out about effects of cousin marriage and why it should be banned? Does that relate at all to the celibate priesthood issue where there was concern about nepotism, or merely coincidental?
Thank you for indulging me.

Fukuyama argued the intent was to increase the likelihood you'd pass your assets onto the Church as opposed to your extended family. This is supported by the fact that children born out of cousin marriage had conveniently precarious inheritance rights.

In some way, there was probably a similar logic with celibacy reducing the incentives for priests to care more about their families versus the Church as a institution.

Discarding the plausible materialist, inheritance hunting explanation (as advanced by above poster) for a second, I doubt that the RCC had any idea of long, down the line potential consequences of cousin marriage (divine inspiration ;)?), but they may well have had some good ideas from experience about how cousin marriage did in concrete, terms affected the formation of clans.

Add to this, as the RCC had a formative in rather a downswing of social organisation to more localised, family network driven affair conflicting with (tentatively?) early Christian and Roman ideas of more expansive brotherhood and citizenship (respectively), that may have been a motivation that was more salient for them than, for example, in Islam, which was driven by the expansion of pastoralist Arabian clans pushing a religion where they were somewhat first among equals (as early adopters, etc.).

Alternatively, rejection of cousin marriage may just have been a Roman norm which the RCC preserved for reasons it did not really know about or understand. Ancient dna will be able to tell us the degree to which this was in fact a norm that changed with influence of the RCC or if this actually had no relevance. (As well as the degree to which consanguinous marriage common in the Islamic world was or was not affected by the rise of Islam!)

I'm not such a vulgar rationalist that I think the Fukuyama argument is solely the story, I think you're right that Christian doctrine, especially in the New Testament, was very anti-family. Wasn't there a famous line about how followers should forsake their families for Christ/the common followershiio, something around "love not your brother as everyone is your brother"

Priesthood celibacy was not much of a reality for the first 1000 years of RCC history, existing as an ideal but not in practice. It started getting enforced in the mid 11th century, not because of nepotism, but because the rising pious middle class demanded that the church start living up to this ideal. And the ideal existed in the first place, not to deal with nepotism, but because the Apostle Paul happened to think celibacy was better than marriage, and because the very early female converts preferred celibacy over an early death through childbirth.

celibacy did not become a formal rule for western clergy until the 12th century, and never was for eastern priests. And the rule was often ignored by priests in rural areas down into the 17th century.

Interested people may read Family and Civilization, by Carle Zimmerman about trustee/tribal families vs. domestic families vs. atomistic families and their relationship to civilization.
Also, the phrase in Genesis: "And therefore a man shall leave his father and mother and shall cleave to his wife" was a clear commandment to break up the kinship tribes.

And frankly, it's a miss for the authors that the paper doesn't at least mention Zimmerman who wrote his book in 1940 with chapters on this very subject.

Just wanted to credit HBD chick as the originator of many of these ideas. Shes somewhat disenfranchised by being an anonymous blogger.

Someone please start a charity that tries to reduce cousin marriage. Emergent ventures?

Here's my January 13, 2003 article in The American Conservative: "Cousin Marriage Conundrum:"

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