Saturday, September 8, 2012

Growing your own merchant class

Sign for an inn, late 17th century, New France. Many merchants began as innkeepers who provided not only accommodation but also other services. (source)

I have just published an article in the journal Advances in Anthropology:  Tay-Sachs and French Canadians: A Case ofGene-Culture Co-Evolution? Comments are welcome.

Tay-Sachs, an inherited neurological disorder, is unusually common among French Canadians from eastern Quebec. Two alleles are responsible, one being specific to the north shore of the St. Lawrence and the other to the south shore. This pattern of convergent evolution suggests the presence of a selection pressure limited to eastern Quebec. Both alleles probably arose after the British conquest of Quebec in 1759 or at least were uncommon previously. To explain the high incidence of Tay-Sachs among Ashkenazi Jews, some authors have invoked heterozygote advantage, i.e., heterozygous individuals enjoy a higher rate of neuronal growth, and thus greater learning capacity, without the neurological deterioration of homozygous individuals. Such an advantage would have helped Ashkenazim perform the mental effort required for work in trade and crafts. A similar situation may have developed in eastern Quebec, where the relative scarcity of British and American merchants made it easier for French Canadians to enter occupations that required literacy, numeracy, and future time orientation.


Frost, P. (2012). Tay-Sachs and French Canadians: A Case of Gene-Culture Co-Evolution? Advances in Anthropology, 2 (3), 132-138.


Anonymous said...

"Two alleles are responsible, one being specific to the north shore of the St. Lawrence and the other to the south shore."

That sounds like something with a lot of significance.

Jason Malloy said...

"Heterozygous individuals should have modestly higher sphingolipid storage and a correspondingly higher IQ, "probably in the order of 5 points" (Cochran et al., 2006: p. 677).
This neural advantage should have helped many Ashkenazi Jews adapt to tasks that require literacy, numeracy, and future time orientation, notably the buying and selling of goods and the making of crafts for urban markets (Cochran et al., 2006; Murray, 2007). Is Tay-Sachs common in eastern Quebec for the same reason?"

The psychometric evidence doesn't seem to provide much support for this.

GSS 2010 IQ/(n):

White 99.5 (20,811)
French Canadian 99.1 (250)
Other Canadian 98.3 (124)

TIMSS 2007 IQ:

Alberta 98.7
British Columbia 98.5
Ontario 99.7
Quebec 98.6

Anonymous said...

I was surprised when you mentioned vitamin D deficiency may have an effect on IQ. Interesting.

My sense is the merchant genes are as likely to influence personality as IQ.

Jason Malloy said...

Dr. Frost responded to my post in a private discussion thread:


You might be missing my point. I'm not saying that a higher frequency of Tay-Sachs indicates a higher mean IQ. I'm saying it indicates that mean IQ has increased rapidly in the recent past over a relatively short span of time."

O.K. Criticism redacted.

Anonymous said...

I think the story that only smart Jews survived pushback from host communities and that's why Jews are supposedly smarter is a myth. If you read the Hebrew Bible you will come upon many stories showing Jewish characteristics that have been described many times since by Jews and non-Jews. So these characteristics were already present thousands of years ago before Jews spread out. Jews whenever they move to a new host community don't do every job required to sustain a community instead they focus on high paying, gatekeeper, and less labor intense jobs while the surrounding host community provides food, protection, money etc. by doing less mental intense, low-paying work. Over several generations you can guess the knowledge and economic gap between those who have high-paying mental jobs versus low-paying physical jobs grows larger and larger. Tay-Sachs probably has very little or zero effect on IQ.

Ben10 said...

A general comment: you test 1 correlation for your hypothesis,
can't you test other correlations?

Adaptation to cold, founder effect, genetic response to the introgression from amerindian genes (lots of quebecois have indian genes), immune response against early exposure to north american pathogens or food.... what else?

Sean said...

Association of serum 25-hydroxyvitamin D3 and D2 with academic performance in childhood: findings from a prospective birth cohort . "The unexpected inverse association of 25(OH)D2 with academic performance requires replication in further studies."

Anonymous said...

Anti-Semitism is a very old phenomenon, as evidenced by the writings of Tacitus and others from the Roman Empire. Anti-Semitism (defined here as action against the most accessible members of the Jewish population) provides enough benefits to Jews that it may be instinctively elicited by Jews; especially by the Jewish leadership which is generally less accessible.

For the purpose of the statements that follow, "anti-Semitism" will be defined as actions against Jews that focus on the most accessible members of the Jewish population.

Since Jews are a multi-territorial nation, sporadic outbursts of anti-Semitism cause small selective pressures to be successively applied to the Jewish population in each ensuing emigration event:

- By preferentially attacking the least wealthy segments of the Jewish community, anti-Semitism selects for mercantile skills.
- By preferentially attacking the less mobile Jews, anti-Semitism selects for hostility toward the territorial boundaries of other nations.
- By preferentially attacking the most locally-dependent Jews, anti-Semitism selects for stronger Jewish identity.
- All of the above select for higher intelligence.

Jewish "chutzpah" instinctively generates anti-Semitism in order to impose the prior evolutionary advantages.

The mechanisms by which instinctive generation of host-population anti-Semitism arose within the Jewish gene pool include the fact that:

- Naked "chutzpah" infuriates members of the host population thereby reducing their intelligence and making them emote. This renders them more exploitable even as it elicits anti-Semitism.
- Defection against a host population is immediately beneficial -- acquiring resources at the expense of the host nation -- and tends to elicit anti-Semitism as a natural by-product.

Kiwiguy said...

OT. but thought this Edge interview with Joseph Henrich on culture and human evolution may be of interest.

Ben10 said...

Some part of Quebec are seriously imbred, so much that a typical 'quebec face' is recognizable in many people. They all look the same because they share the same genes, as well as any associated mutation.
I watched a documentary about Robert Lepage recently (The Rheingold) and beside the fact that his weird look is caused by a 'rare form of alopecia' (cf. wikipedia) , he has a typical quebec facial bone structure.
And he's smart.
So, any rare genetic condition like TS or other rare mutation can be explained by founder effect and too much, ahem, inbreeding, although it is very likely that Lepage has some indian or british/irish blood.

Peter Frost_ said...


Tay-Sachs is specific to Ashkenazi Jews, as are several other related neurological disorders. It doesn't occur in Sephardic Jews, at least not to an unusual degree. So I don't see how antisemitism could play a role, unless one is arguing that Sephardic Jews were not targets of antisemitism.


Very interesting. I wish I could have referenced that study in my article. Henry Harpending is doing some work in that area, so I'll have to let him know.


Interesting interview. I get the impression that the two of us have been reading the same authors. I'm going to keep an eye on him and his publications.


- The Tay-Sachs allele is not present in Amerindian populations.

- inbreeding is also common in much of western and central Quebec, yet the Tay-Sachs allele is not particularly common in those areas. Please note: inbreeding doesn't affect the frequency of an allele. It simply increases the likelihood of homozygosity.

- a founder effect does not easily explain why two different variants of Tay-Sachs have appeared in Quebec. Lightning doesn't strike twice in the same spot.

- adaptation to cold? But what about the other regions of Quebec?

- The early European settlers brought plenty of pathogens with them. I'm not aware of any that were introduced by the Amerindians (syphilis was once thought to be a New World import, but that hypothesis is no longer widely accepted)

JayMan said...

See also both HBD Chick's and my discussion of the French Canadians.

Ben10 said...

"a founder effect does not easily explain why two different variants of Tay-Sachs have appeared in Quebec. Lightning doesn't strike twice in the same spot."

Maybe it did, or maybe the two alleles were created at the same time. How old are they, can you date them?
I guess 350-400 years is the oldest possible, since that's the age of the population in quebec but maybe the two alleles have slightly different ages.

Anonymous said...


Off-topic but...

Could it be that Jews regardless of their country of origin-Ashkenazi and Jews of Iraq, Iran, Yemen, etc have elevated intelligence levels? Persian Jews in the United States have obscene amounts of wealth and are well educated. Great Neck, NY, home to the Persian Jewish community has some of the best schools in the country. Tay-Sachs and all of the other disorders are irrelevant in explaining high Jewish IQ, because high IQ is not limited to the Ashkenazi.

Steve Sailer said...

Quebec is a pretty good success story over the last half century, not too dissimilar to Finland, although in a more propitious location.

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