Ashkenazi intelligence

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Ashkenazi Jews are the Jews of Central and Eastern European origin, the descendants of Jews who settled in the Rhineland beginning about 800 CE. It is also believed that Ashkenazi Jews have some connections with the Kirimchaks of the Khazar empire.^{[citation needed]}

Many studies show that Ashkenazi Jews, on standardized tests of general intelligence, have the highest average IQ scores of any tested ethnic group, being roughly one standard deviation higher than the mean of the general white Caucasian population.[4] These studies also indicate that this advantage is primarily in verbal and mathematical performance; spatial performance is mediocre.

Ashkenazi Jews achieve out of proportion with their numbers in areas that presumably require high intelligence. For example, although Ashkenazi Jews represent only about 0.25% of the world population, they make up 28% of Nobel prize winners in physics, chemistry, medicine, and economics, and have accounted for more than half of world chess champions.[5] In the United States, Ashkenazi Jews represent 2% of the population, but have won 40% of the US Nobel Prizes in science, and 25% of the ACM Turing Awards (the Nobel-equivalent in computer science). A significant decline in the number of Nobel prizes awarded to Europeans and a corresponding increase in the number of prizes awarded to US citizens occurred at the same time as Nazi persecutions of Jews drove them from Europe during the 1930s and the Holocaust reduced their number in Europe during the 1940s.[6]

Whether this difference in measured intelligence and achievement is due entirely to a culture of study and vocational training (environment), or partially to a difference in genetic variables, is presently unknown and controversial. (See Race and intelligence.)

1 Cochran et al.
2 Other theories
3 Criticism
4 Notes
5 References
6 External links

[edit] Cochran et al.

A 2005 study by Gregory Cochran, Jason Hardy, and Henry Harpending at the University of Utah [7] notes that European Jews were forbidden to work in many of the common jobs of the middle-ages from C.E. 800 to 1700, such as agriculture, and subsequently worked in high proportion in meritocratic jobs requiring higher intelligence, such as finance and trade, some of which were forbidden to gentiles by the church. Those who performed better are known to have raised more children to adulthood, according to Cochran et al., passing on their genes in greater proportion than those who performed less successfully.^[1]

Cochran et. al. hypothesize that the eugenic pressure was strong enough that mutations creating higher intelligence when inherited from one parent but creating disease when inherited from both parents would still be selected for, which could explain the unusual pattern of genetic diseases found in the Ashkenazi population, such as Tay-Sachs and other sphingolipid diseases. Some of these diseases have been shown to correlate with high intelligence, and others are known to cause neurons to grow an increased number of connections to neighboring neurons.^[2]

Reviews of the controversial paper have been both positive and negative, with critics claiming the argument to be far-fetched and unsupported by direct evidence.[8] Supporters of the paper, however, saw the critique as an example of scientifically justified prejudice. Seeing the presumption that race cannot cause IQ differences, as prejudice.

[edit] Other theories

There have been other theories along similar lines. One theory notes that for Jews to be socially successful in their peer group, expertise at Torah study has traditionally been an advantage, and since the Enlightenment, those Jews lacking the intellectual skills for this endeavour may have been more prone to assimilate into general culture, thus leaving the reproductively-isolated Jewish population.(Murray 2003, Shafran 2005)

In general, among religious Jews, study of Judaism (especially, Talmud) is historically a required and praised everyday activity (not only among rabbis and Torah scholars). When Jewish families became secularized, the tradition of constant study of Judaism was replaced by a tradition of rigorous secular studies, which by itself became a part of the culture. As the number of generations between the transition to the secular life style increases, the intelligence of the generation approaches the average national intelligence, as the generations assimilate into the general culture, in which education is less favored.

In addition, Jewish families usually had many children. The wealthiest families tended to be more educated (it was a common practice for wealthy Jewish merchants to encourage young successful Torah scholars to marry into their families and then support the scholars' studies for several years after the marriage). This may have propagated not only the tradition of education, but also the genes associated with the higher intelligence.

It has been suggested that European Jews' history of persecution created social selection for high intelligence, leaving a positive effect on the hereditary component of their IQ.^[3] Others say that, due to this persecution, Jews emphasized education, an asset that is transportable. In this way, they could adapt better in new locations. This hypothesis is not mutually exclusive with others, because human intelligence is influenced by genetic as well as environmental factors. Certainly, outstanding success in chess and mathematics-heavy sciences requires an above-average capability for memorizing a large number of complex and abstract formulae (a function of intelligence that only in comparatively recent times can be utilized to the fullest). Either a favorable genotype, or an upbringing that placed high emphasis on study and learning-by-heart of lengthy, abstract and complex treatises such as the Talmud, or a combination of both will provide a better-than-average foundation for such success.

[edit] Criticism

Criticism levelled against the interpretation of supposed Ashkenazi intelligence superiority claims can be summarized thusly:

the accomplishment in numerous science-related fields is not necessarily highly correlated with general IQ, nor N and V factors. What matters more is creativity, combined with motivation and capacity for sustained work. It is well known that one of the greatest mathematicians in history, Henri Poincaré, performed poorly at intelligence tests. Also, Albert Einstein did not possess mathematical memory above the average, nor was he an outstanding mathematician lege artis. What distinguished him was a physicist's intuition and a rare strength in "imaginal thinking"- a power to visualize abstract concepts. Both these features are not measured in standard intelligence tests.

the "contribution far above the population percentage" argument is an extremely tenuous one. It can be easily verified that giants of post-Renaissance exact sciences are Gentiles coming mainly from three countries: Britain, Germany and France. It would be preposterous to assume that this has something to do with "national intelligences" of these countries, rather than with complex welter of socio-cultural and historical factors.

[edit] Notes

^ The Jews rarely married outside of their faith, creating a reproductively isolated population in which, in the statistical models of Cochran and his co-authors, this pressure would be able to influence gene frequency over nine centuries and 35 generations.
^ Patients with torsion dystonia (relatively common in Ashkenazi Jews), for example, are reported to have an average IQ of 122.[1]
^ See the NYTimes coverage for more information.[2] Cochran et al. 2005 is forthcoming in Cambridge's Journal of Biosocial Science. [3]