Integration seems one of the great political issues of our era. That is, people express great concern about factional favoritism based on race, ethnicity, religion, class, gender, age, etc., and push for laws and policies to prevent it, or to encourage mixing and ties across factional boundaries. I’ve tended to assume that such policies have been sufficient, and perhaps even excessive.

But a student, Randall McElroy, wrote a paper for my grad law & econ class, that got me thinking. He wrote about how the Hopi indians dealt with mass immigration in part by defining newcomers as a new clan, and then forbidding within-clan marriage. Such “exogamy” has apparently been a common strategy in history: force mixing and friendly ties between factions by requiring all marriages to be between factions.

I was reminded of Cleisthenes redesigning the political system of ancient Athens to break up the power of region-based alliances that had caused endemic political conflict. He created ten equal tribes, where a third of each tribe was taken from a different type of region, plain, coast, or hills, and made these tribes the main unit of political organization.

Cleisthenes’ approach had seemed drastic to me, but its costs were small compared to the Hopi approach. After all, the costs of substantially limiting who people can marry must be very high. So many societies must have perceived even higher costs from factional divisions. Which makes sense if, as I’ve suggested, coalition politics is central to human sociality. So I’ve raised my estimate of the costs induced by factional favoritism.

I still expect that our factional divisions are mild enough for mild policies to be sufficient. But if I’m wrong, we might consider at least a mild form of exogamy: financially subsidizing marriages between distinct defined factions. We could similarly subsidize other close relations that mix factions, such as roommates, or interacting closely in the same church or workplace.

How would people would react to such suggestions? I see very different reactions depending on the faction in question. Many are quite ok today with requiring marriages to be between genders, but not out of concern for factional politics. Many would be ok with subsidizing marriages between races and ethnicities. But many would object to subsidizing marriages between ages or classes, as they see existing examples of this as exploitive or disgusting, and try to discourage them via informal social pressures.

Many would object to subsidizing marriages between religions, seeing it important for couples to share a common religion. Relatedly, the US today is becoming increasingly split geographically by a “red vs. blue” ideological divide, and I’d expect many would object to subsidizing marriages across this divide. After all, many live where they do because they want to live with their own kind, and don’t like to mix with “those people.”

Our lack of interest so far in exogamy solutions makes me suspect people don’t think our factionalism problem is especially serious. Expressing concern about ethnic or religious factionalism is probably often used as a way to say “rah the liberal faction,” as that faction is seen as caring less about ethnic or religious factions. I suspect this is a general pattern: policies to reduce factionalism along some dimensions are usually pushed because they favor particular factions along other dimensions. Which doesn’t mean such policies can’t have net benefits.

Overall, my guess is that factionalism in our society will have to get a lot worse before we are willing to consider solutions like exogamy that other societies have used to deal with such problems. We don’t now see a big problem.