Nathan Cofnas wrote a paper [ Science is not always “Self-Correcting” ] on how various scientists and philosophers choose or reject scientific theories about human intelligence. Not just quietly avoiding truths they don’t like, but explicitly saying that everyone should do so. Reminds me of a New Mexico politician [ Patricia Madrid] that filed charges against guys that had bribed two state treasurers, but had been given immunity in return for their testimony by the Feds. Not a proven thief, last I checked – but a principled proponent of theft. Probably a paid spokesman for the Thieves’ Guild. I voted for her, by the way, when she ran for this Congressional seat.

Let us name some names. Jared Diamond, Howard Gardner, Philip Kitcher, Ned Block and Gerald Dworkin, Noam Chomsky, Robert Sternberg, Eric Turkheimer, Richard Lewontin. And not forgetting to speak ill of the dead, Steven J. Gould and Leon Kamin.

A number of these guys clearly believe that there are racial differences in average intelligence that need to be hidden. For example, Howard Gardner (2001) writes that he does “not condone investigations of racial differences in intelligence, because [he] think[s] that the results of these studies are likely to be incendiary.” Well, if it was shown that no such differences existed, that would hardly be incendiary. Surprising, maybe, but not obviously incendiary. Or if we found that people in New Guinea mentally towered over everyone else [The Masters of the Future], that would apparently be just fine. Clearly, Gardner believe that such differences likely exist, differences large enough to matter, and that their pattern is not one that people at Harvard would be happy to see. So why haven’t they fired him? There are those that suspect his work in general is probably not correct – in fact, Gardner himself seems to suspect this. ” [E]ven if at the end of the day, the bad guys [such as Jensen, who emphasize the importance of g,] turn out to be more correct scientifically than I am, life is short, and we have to make choices about how we spend our time. And that’s where I think the multiple intelligences way of thinking about things will continue to be useful even if the scientific evidence doesn’t support it.”

Eric Turkheimer seems to think that the possibility of racial IQ differences is refuted by an “ethical principle that individual and cultural accomplishment is not tied to the
genes in the same way as the appearance of our hair”. That’s an odd argument. Does it work with Downs and Fragile X? I doubt if he has ever used it for any other issue. Should I use it to deny the possibility of a nuclear chain reaction, or smallpox epidemics, or asteroid strikes? If he thought that there just weren’t any such differences, he wouldn’t need special new ‘logical’ principles to prevent them from existing – would he?

Philip Kitcher advocates raising the bar for evidence supporting theories he doesn’t like. I’ve talked about this [The Veeck effect]. Why do you think he makes this argument? If populations really were effectively the same in IQ, there would be lots of easily observable evidence for it. No way to prove exact equality, but it wouldn’t be hard to show that group A and B were close. But nobody does, because nobody can. If this were true, it would show up in a genetic admixture study: so nobody will do one.

You would not see anything like the patterns we actually experience – you wouldn’t see a single family ( like the Bernoullis or Braggs or Bohrs) be competitive with a whole race at at the highest intellectual level. You do see that in running – girls from a single town in Ethiopia can beat every female in China – but that’s not equality.

Only a few of these people are old-fashioned, deep-fried Marxists – Gould was and Lewontin is. Of course Marxists lie: they believe in it. And they have to, because reality hasn’t been all that favorable to their cause. The future of Marxism is in VR.

So what must be done? If a researcher is a liar and isn’t particularly interesting, sure, fire him. That probably applies to nearly everyone on this list. But sometimes the liar is also a genius: what then? What about Haldane?

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Reach for a Camel instead of a sweet

The Nazis were against smoking well before it was cool. Therefore…

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Sometimes a population has effective adaptations that protect against a very serious local problem – a problem so serious that outsiders that don’t have those special adaptations cannot invade, at least not without a fair amount of gene flow from the locals. Due to tropical diseases, much of Sub-Saharan Africa was like that.

We know that one of the key alleles in the Tibetan altitude response comes from Denisovans, which implies that some Denisovans spent a long time at high altitude. Suppose that they occupied Tibet. Could modern humans have invaded Tibet? Even if they could, might it have taken much longer than elsewhere? Might Denisovans have lingered longer in Tibet than elsewhere?

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Physical Anthropology: they already knew

gcochran9 says:
June 20, 2016 at 11:06 am (Edit)
All of Southeast Asia was occupied, relatively recently, (~6000 years ago) by populations that were genetically close to the Andamanese and to the funny admixture fraction in Brazilian Amerindians. Closer than anyone else, anyhow.

Frank says:
June 20, 2016 at 1:18 pm (Edit)
I’m sorry. I guess I didn’t yet read that ancient DNA paper on Southeast Asia.

Here it is. “We find that early genomes from Hoabinhian hunter-gatherer contexts in Laos and Malaysia have genetic affinities with the Onge hunter-gatherers from the Andaman Islands, while Southeast Asian Neolithic farmers have a distinct East Asian genomic ancestry related to present-day Austroasiatic-speaking populations. We also identify two further migratory events, consistent with the expansion of speakers of Austronesian languages into Island Southeast Asia ca. 4 kya, and the expansion by East Asians into northern Vietnam ca. 2 kya.”

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Subtleties of Sickle-Cell

Sickle-cell is a standard textbook example, but there are subtleties that those texts never mention. Not just the point about the advantage of early lethality in homozygotes.

Ask yourself why, over thousands of years, falciparum malaria never became resistant to this genetic defense.

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Better off dead

A recent paper on the origin of sickle-cell was being discussed, and an interesting question was posed [ by Razib Khan]: why haven’t modifier genes emerged that reduce the bad effects in homozygotes?

Let me say something about those bad effects. The most important one is that someone with sickle-cell disease usually has a ruined spleen before the end of childhood – infarcts. This enormously increases the risk from encapsulated organisms like pneumococcus: in a place or time without effective medical care, this kills you. There are all kinds of other problems that eventually show up if effective medical care gets you over that first hump, but in the past, and in many places today, kids with sickle-cell diseases usually didn’t make it past two.

What about a mutation that led to a milder form, one with the same positive effects in heterozygotes but that that killed homozygotes at age five, instead of two? It would not be favored by selection: five year olds don’t produce any offspring, and they use up more parental resources. Killing homozygotes rapidly (as opposed to slowly) increases the fitness of the sickle-cell allele – it lets the parents start over and produce another kid, who might be a carrier.

There’s a malaria defense in Southeast Asia, Melanesian ovalocyosis, that goes all the way – homozygotes die before birth.

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Genetic Arguments

Every now and then someone tries to give some genetic argument showing that population A and population B can’t possibly be significantly different in any trait that hurts someone’s feelings. They’re all bullshit.

The most famous one is probably Lewontin’s Fst argument. He said that since most (> 85%) genetic variation in humans is within-group, rather than between groups, human populations can’t be very different. Except for traits influenced by a few genes, like skin color, or a single gene that affects many traits, like EDAR, or a highly polygenic trait influenced by many genes, like height. That is, any kind of trait, with any kind of genetic architecture.

A related argument says that you only see differences in ‘superficial’ traits, like bone density, brain volume, or the shape of the skull. That’s sarcasm.

Another says that populations just haven’t been separated long enough to diverge much. Untrue: selection can move pretty rapidly. Amerindians have undergone noticeable genetic change (mostly immunological) over the past five hundred years. While some human populations been separated for much longer than that: often tens of thousands of years, sometimes (with Bushmen for example) hundreds of thousands of years. Plenty of time.

Lately I’ve seen a few people arguing that there can’t be big between-population differences in highly polygenic traits, those influenced by many alleles of small effect, because evolution of a highly polygenic trait is for some unknown reason very slow -” at least 100 millennia to evolve appreciably”. But that isn’t the case.

They’re thinking about intelligence – but height is also polygenic. Yet Pygmies and Tutsi exist. For that matter, natural selection over the past few thousand years has made southern Europeans shorter and northern Europeans taller.

I have no idea where this notion originated, because there’s nothing in genetic theory or practice that supports the idea that polygenic traits can’t change rapidly. Think of the Maltese elephants, isolated when sea level rose at the end of the ice ages: 3 feet tall in just a couple of thousand years.

While there are many counterexamples in agricultural genetics: you can breed for almost any trait* – appearance, conformation, size, disease resistance, flavor, behavior – and we have done so. Many of those traits are highly polygenic. In fact, Fisher’s infinitesimal model, fairly standard in evolutionary genetics, assumes that an infinite number of alleles influence a trait.

Most of these fallacies are addressed in the tome I’m perusing. The author correctly dismissed all of them. But then…

* except sex ratio. That’s nearly impossible.

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