How a one-in-400million disability became common in a tiny polygamist Mormon town after...

Cure for the future - abandon the community, leave, at once, and get out in the world and marry someone from outside the exclusive community.

Somewhere I read that when the railroads started up in the UK, the gene pool was rejuvenated as people were able to leave their homesteads and go far afield. Maybe an Urban Legend, but it sounds right to me. Any time the population of an area goes insular, things go downhill.

>> when the railroads started up in the UK, the gene pool was rejuvenated <<

Fascinating hypothesis!

Ought to be tested rigorously, say in a cross-country study, by an econometrician who works with historical data. Seriously!

But due to the politico-cultural “sensitivity” of the genes-IQ connection, it’s probably not a subject that can safely be researched by anybody with an academic affiliation.

Fascinating hypothesis!

Indeed. Wife and I were just talking about this and we were wondering if part of the problem with the Dark Age was that people rarely traveled outside their village then and would face the same inbreeding problem.

I think it was a National Geographic TV episode that told of how men from different nearby tribes would assemble in a neutral "village square" and squat down, exposing their genitals while the women circled them and indicated their preference by tapping them on the shoulder. The show stressed that it was to spread the genes around so that each tribe had blood from the others and thereby lessen the reason for conflict, and as a side effect, lessen the inbreeding problem.

>> we were wondering if part of the problem with the Dark Age was that people rarely traveled outside their village then and would face the same inbreeding problem <<

Agreed. Social mobility and a lot of “out-breeding” should increase genetic diversity and thereby lessen the dangers of recessive-gene-induced mental and physical defects.

But then there’s a possibility that social mobility can, beyond some point, lead back to increased inbreeding.

In this regard, Charles Murray discusses the potential downside of “assortive mating” — which is the sort of thing that happens for example when one genius-level scientist marries another genius-level scientist that he met while in graduate school. The offspring of such super-IQ unions seem to suffer from autism more frequently than the “averages” would predict. This phenomenon may explain why there’s a high incidence of autism in the Silicon Valley.

Moreover, as high IQ people find increased opportunities in big cities and at universities to meet and mate with other high IQ people, the low IQ people in our society are led more and more to marry one another, as opposed to the old days when most kids just married somebody from a neighboring farm.

Therefore, to the extent that IQ is postively correlated with income, assoritive mating may mean that the rich get richer, while the poor get poorer.

In other words, so as far as genetic diversity is concerned, maybe there ain’t no free lunch!

Of course, there’s no single gene for IQ. No doubt “quickness” or “sharpness” of mind, as popularly perceived, is closer to an inheritable trait, but who knows what the actual genetic contributions are.

To be honest, as a grandparent, my view of early human development tends toward the miraculous.

... “It’s all too beautiful! It’s all too beautiful!” - Itchycoo Park

I have no idea but wouldn’t you think the further back you go the less the DNA would have mutated or changed from the original? I would think that might be an explanation as to why it wasn’t a big deal then. Just my idea as to why inbreeding was not a big deal then; I also think that is why so many had very long life spans. Less to go wrong.

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