What aspect of the article is discomforting?

Clearly, Daniel, you have been infected by the PC virus. That an idea "dare not speak its name" and makes you uncomfortable can only be the result of years of conditioning. Yes, all men ARE created equal in the sense of having equal rights in society. No, all men are not created equal in the sense of having equal abilities. The idea that academics dare not say so makes me very uncomfortable.

Now anti-Semitism and anti-intellectualism have something in common.

There is an interesting article about the infection/homosexuality speculation here.

I don't have a clue what causes homosexuality. It doesn't seem to be inherited, even though the tendency appears in adolescence. There is no obvious link to any particular kind of upbringing, inasmuch as most homosexuals have straight sibling.

So maybe there is a infection by a still-unknown agent. I haven't heard of any evidence for the theory, but I don't consider it preposterous.

Or perhaps space aliens are to blame?

On homosexuality, the latest hot idea seems to be it's caused by hormonal changes in the mother that occur after the birth of her first son - a large number of gay men have older (straight) brothers, and very few first sons are gay.

Dan's not wrong to be uncomfortable. If Jews are smarter because of past selection pressure and history, we can't be far away from some comedian (if we're lucky) blaming American black underacheivment on the fact "they're the descendants of the ones too dumb not to get enslaved." Or more subtley, someone will compare the economies of the West to those of traditional societies and how the former might reward intellectual achievment and provide greater reproductive success to the intelligent, while the rest favor as a relative matter physical strength or simply perpetuate historical caste/clan relationships. How many generations before a statistically significant variance in IQ develops between the populations?

There's an interview with Cochran about the theory of infectious causation of homosexuality here.

There's also a brief discussion (a little more than one page out of 40) in his research paper with Paul Ewald.

I don't see why it's "strange."

If Jews are so much smarter than everyone else, then why do I feel so stupid?

Perhaps I have an inferiority complex. If so, then Freud should be able to help, since he's so smart (he's Jewish, see...)

But, Freud's been debunked or superseded, depending upon whom you ask.

What are we left with?

In Joel Mokyr's "Lever of Riches" he mentions an idea that was once put forth by one of his colleagues - though I can't remember who specifically and I don't have the book with me right now - that I think is at least a plausible alternative hypothesis.

Basically the argument is that since the Jews constantly faced expulsion and expropriation it made no sense to invest in assets which were likely to be grabbed away - no sense in investing in land, or physical capital. It made sense to invest in something which could not be taken away because you always carried it with you - human capital, education, etc. So a culture of learning and scholasticism developed.

From a point of view of an economist I think this is a far better story. It relies on people responding rationally to incentives without supposing any inherent biological or genetic differences. And I haven't read Cochran's paper but any theory which argues for some kind of link between the long, drawn out and often unpredictable process of evolution and something so tenously defined and very imperfetly understood as 'intelligence' smells fishy to me.
I think Dan's bothered by the fact that these kind of arguments, despite their obvious weaknesses, can be easily flipped and used to argue something much more nasty. If you accept that some particular group is inherently 'smarter' then obviously the implication is that some groups are inherently 'dumber'... and that's an ugly road which is also unfortunetly well travelled.

Chris Rock wrote: "If Jews are smarter because of past selection pressure and history, we can't be far away from some comedian (if we're lucky) blaming American black underacheivment on the fact 'they're the descendants of the ones too dumb not to get enslaved.'"

Which is clearly absurd, since they were also descendants from the ones too slow to run away from their captors, and yet are some of the greatest track stars in history (she said, tongue in cheek).

"Chris Rock" said:

> How many generations before a statistically
> significant variance in IQ develops between the
> populations?

That already appears to have occurred, according to the book IQ and the Wealth of Nations, by psychologist Richard Lynn and political economist Tatu Vanhanen. The simple correlation between National Average IQ and (log) GDP per capita turns out to be about +0.8.

And the statistical relationship between national average IQ and national economic performance seems to be extremely robust, as psychologist Joel Schneider and I show here:

http://www.siue.edu/~garjone/JonesSchneApr.pdf
In that paper, we ran 1330 different economic growth regressions. IQ always had a positive relationship with growth, and it was statistically significant 99.8% of the time--better than just about any other economic variable you can find. The IQ-growth link isn't just a fluke.

I've got another paper that digs deeper into the reverse causality angle here:
http://www.siue.edu/~garjone/naive.pdf

Now, I don't claim to know why IQ varies so much across countries--nutrition and education certainly play a role--but I do know that IQ differences across countries are big enough to matter.

Case in point: One IQ point is associated with a 6.7% higher standard of living in a country--and when you consider that the IQ gap between rich and poor countries is at least 30 points, that adds up to a 650% difference in living standards. Too big to ignore.

So that's why Jews appear to be so smart and successful. I originally attributed this phenomenon to a nefarious Zionist conspiracy but it appears I'll have to rescind this conclusion.

Seriously though; I don't think anyone's challenging the notion that Human beings are diverse, and "some are more equal than others" if you will, but what the factors are for this diversity. The ol' Nature vs. Nurture.

As for the homosexual germ issue, man is the right ever gonna love this one. Call me pessimistic, but I doubt that the more hard-line Christian & Social conservatives are going to wait long for substantiative of this before they start talking about people being afflicted with the 'homosexual disease', and how the germ is ravaging their brain.

Radek: "So a culture of learning and scholasticism developed."

There was an article in the last year on Opinion Journal (I think) discussing this idea under the heading of "why Jews don't farm." But the added point was that those historical Jews who couldn't hack the "culture of learning and scholasticism" tended to "drop out" and fade into the larger Christian community. So those genetically smarter or predisposed to the culture stayed Jewish, and the "dumb" or at least anti-intellectual genes left the Jewish gene pool. So culture still drives genetic development.

Well, Dan, it loks like you've been discovered.

"They also suffer more often than most people from a number of nasty genetic diseases, such as Tay-Sachs and breast cancer... [which] was seen as a consequence of genetic isolation. Even now, Ashkenazim tend to marry among themselves. In the past they did so almost exclusively."

Actually, he's got his facts wrong. First of all, Ashkenazim are already more genetically diverse than Sephardim, being a mixed population, Middle Eastern and European. Second of all, incidence of Tay Sachs has been drastically reduced, virtually eliminated, due to the relatively high rate of assimilation.

If the reported IQ difference is correct and if it in fact is a consequence of natural selection, would it imply that high IQ Jewish males and females, relative to less high IQ Jewsih males and females, were more likely (1) to breed, (2) to breed with each other, and (3) to have more surviving offspring?

How long (how many generations) would something like take to have an effect? 4000-5000 years? Or if it's only Ashkenazim, then what, 800-1200 years?

Well, I'm an Ashkenazy Jew and clearly a genius, so I guess the article is correct.

1) you can read the full paper here. confirm or disconfirm your uneasiness by getting it from the source.

2) Actually, he's got his facts wrong. First of all, Ashkenazim are already more genetically diverse than Sephardim, being a mixed population, Middle Eastern and European. Second of all, incidence of Tay Sachs has been drastically reduced, virtually eliminated, due to the relatively high rate of assimilation.

a) greg knows about the admixture (read the paper, the guy who wrote the economist piece had his own ideas). and it isn't really accurate to say they are more genetically diverse from what i have seen, the "sephardim" are a heterogenous population themselves. in any case, there could have been an initial admixture event, after when they didn't outmarry much.

b) as for tay sachs, it has been "eliminated" because carriers are encouraged not to marry or at least have children in the jewish community, because the children have a 1/4 chance of having the disease. the frequency of individuals carrying the allele remains the same, because heterozygotes don't die.

This theory may make Dr. Drezner feel uncomfortable, but not as uncomfortable as one of these Ashkenazi hereditary diseases can make their victims. This paper provides a new theory for understanding these diseases. If it pans out, it could open the door to better treatments of patients suffering from these afflictions.

Dr. Drezner is correct to be uncomfortable. The hypothesis that some form of selection for intelligence is responsible for the relatively high incidence of some inherited diseases among Ashkenazim is exactly that, a hypothesis. This hypothesis is also, at best, only indirect support for the idea that Ashkenazim are more 'intelligent' than other ethnic groups. There are very reasonable and probably better explanations for the high incidence of these disorders in Ashkenazim, namely founder effects. These alternative hypotheses have been supported by significant research by very, very competent geneticists. Neil Risch, a very well known statistical geneticist, has worked in this area and his work supports the founder effect hypothesis.
Founder effects occur when relatively reproductively isolated populations are started by relatively small groups. If one or more of the small group of founders carries a specific inherited disease, later generations will express the inherited disease at a relatively high level. French-Canadians, for example, descend from a relatively small number of founders and there are some inherited disorders that occur at relatively high levels in modern French-Canadians. Selection effects can be demonstrated in human populations, for example the relationship between sickle cell trait and malaria resistance, but demonstrating selection effects in human populations is difficult.
There is evidence for heritability of intelligence, but there is little good evidence that specific ethnic groups are enriched in whatever genetic factors influence intelligence.

I have written a critical review of "The Natural History of Ashkenazi Intelligence," by Gregory Cochran, Jason Hardy, and Henry Harpending.

You can find my review here:

An Unnatural History of Jewish Population Genetics
http://metzenberg.judaismo.org/cochran_harpending/

Roger: you are correct that demonstrating selection effects in human populations is difficult.

But that's precisely why the paper is such a big deal. For perhaps the first time in history, we have a true testable hypothesis. If you're right about founder effects, most or all of the untested sphingolipid/DNA repair diseases won't have anything to do with intelligence or IQ. Conversely, if they all do, the only plausible explanation is that selection, rather than the founder effect, is in fact responsible.

This would NOT prove the historical speculation of the paper; it would just prove beyond any reasonable doubt that intense natural selection for intelligence has occurred among Ashkenazim. But that happens to be a thousand times more relevant than the truth of the historical speculation anyway.

Actually, no. Lets try the reasonable experiment you propose. If heterozygous carriers of these disease alleles aren't more intelligent than wildtype homozygotes, this is evidence against selection for intelligence as driving the relatively high incidence of these disease alleles among Ashkenazim. This wouldn't, however, exclude other selective effects causing the high incidence of disease alleles. Now, what happens if there is an association between heterozygous allele carrier status and intelligence. Does this demonstrate a selective benefit? No, the high incidence of disease alleles could still be the result of founder effects/drift and the effect on intelligence an epiphenomenon. As is often the case with complex models incorporating a lot of speculation, its hard to produce really useful predictions from this set of ideas.