Who would have thought that bones found at the bottom of a medieval well in England could stir up such debate and possibly rewrite both history and science?
DNA analysis of human remains from England published in August has illustrated the ability of our genes to upend centuries of belief. More specifically, it provides fresh insights into both a specific historical anti-Jewish atrocity while spurring a rewrite of an otherwise obscure dimension of the genetic history of Ashkenazi Jews.
The research also has cast doubt on a much-debated theory of Jewish intellectual exceptionalism — that the high cognitive abilities of Ashkenazim, as evidenced by IQ scores or the disproportionate number of Jewish Nobel laureates is the result of genetic natural selection for increased intelligence.
Jewish IQ debate
Ashkenazi Jews (Jews who ultimately settled mostly in Central and Eastern Europe after leaving the Middle East and Italy during the first millennium), despite being a tiny 0.19% percent of the world’s population, make up more than 20% of all Nobel Prizes and 25% of the ACM Turing awards. They have an average IQ of 107-115 — a full standard deviation higher than any other religious or ethnic group — and an average of 123 in the verbal category (a fact suggested by some as a possible explanation for the high number of Jewish comedians).
Among people in the “genius” category, with IQs of 130 or higher, Jews outnumber members of other ethnic or religious groups 45 to one. In the verbal category, the Jewish average is 123, significantly above the rest of the population. the highest SAT scores of any group. They make up more than 20% of the CEOs of top US companies, and 30 percent of Ivy faculties. These “Jewish achievements” have come while being among the most persecuted groups during the second millennium.
What might explain these outsized performances? A controversial theory — Natural History of Ashkenazi Intelligence, published in the Journal of Biosciences in 2005 by anthropologists Gregory Cochran, Jason Hardy and Henry Harpending, provoked immediate controversy; or, as Harvard psychologist Steven Pinker described it in a subsequent critique, “The [Cochran, Hardy and Harpending] study quickly became a target of harsh denunciation and morbid fascination”.
It is not difficult to appreciate why. As Pinker goes on to explain, “any characterization of Jews in biological terms smacks of Nazi pseudoscience about ‘the Jewish race’”. Not surprisingly, even (or especially) today, mention of this theory still raises hackles. (It is worth noting that Harpending, who died in 2016, is listed by the Southern Poverty Law Centre as an “extremist” with “White Nationalist” ideological beliefs, with Cochrane described as his “frequent collaborator”.)
But to understand what has this to do with the more recent genetic study of medieval human bones, we need to go back to the year before the Ashkenazi intelligence paper first appeared.
Uncovering a medieval massacre
In 2004, during construction work in Norwich, England, the skeletal remains of at least 17 people were found in what was believed to have been a medieval well. Radiocarbon dating placed the remains in the late-11th/early-12th century, with the skeletons’ position and completeness suggesting they were all victims of a single mass fatality.
These archaeological dates overlapped with a recorded antisemitic massacre, in 1190, in which an unknown number of the city’s Jewish community were murdered during a period of bloody Jewish persecution. (Slightly earlier, in 1144, in one of the first documented cases of the notorious ‘Blood Libel’ conspiracy, Norwich’s Jews had also been accused of ritually killing a Christian child.) In 1290 King Edward I expelled every Jew from England, the first time this had happened anywhere in Europe. Thousands of men, women and children were forced to leave for the Continent and Jews were not officially allowed to live in Britain again until 1655.
This cartoon above depicts a wealthy Jewish money lender in Norwich. Note he is pictured with horns and a triple beard to associate him with the devil, and to suggest sexual excess. Demons were often linked to the seduction of women, so again this is a very negative portrayal of a Jew.
The recently-completed genomic analysis of six of the skeletons confirmed that they were indeed Ashkenazim (three were sisters, the youngest as young as 5-years-old) and thus were the likely victims of Norwich’s “historically attested episode of antisemitic violence”.
From the perspective of how rapidly genetic biology is revolutionizing history, archaeology and anthropology, this research is yet another breath-taking example of the way ancient DNA analysis can advance our understanding of the past; it follows that of the famous identification of the body of King Richard III in Leicester in 2014, with the field further galvanized by the recent award of the Nobel Prize to DNA expert Svante Pääbo. More narrowly, however, the Norwich research has also been particularly enlightening about the genetic heritage of Ashkenazim (according to the Norwich study’s authors, “No genomes from known Jewish individuals are currently available from the medieval period or earlier, largely because exhumation and scientific testing of Jewish remains are prohibited”).
The study has yielded some important medical and historical insights. For example, certain genetic disorders found with high frequency within modern Ashkenazi communities (including Tay Sachs, Nieman Pick and Gaucher syndromes) were also prevalent among their medieval counterparts. Previously, these diseases were thought to have arisen much more recently — and this is where the controversial evolutionary hypothesis on Jewish intelligence comes in.
Evolution of Ashkenazi intelligence?
In his commentary on the Natural History of Ashkenazi Intelligence, Steven Pinker briefly summarizes Cochrane, Hardy & Harpending’s position:
[Their paper] proposed that Ashkenazi Jews have a genetic advantage in intelligence, and that the advantage arose from natural selection for success in middleman occupations (moneylending, selling, and estate management) during the first millennium of their existence in northern Europe, from about 800 C.E. to 1600 C.E. Since rapid selection of a single trait often brings along deleterious by-products, this evolutionary history also bequeathed the genetic diseases known to be common among Ashkenazim, such as Tay-Sachs and Gaucher’s.
While insisting that the Utah researchers’ evolutionary argument “meets the standards of a good scientific theory,” Pinker said that “it is tentative and could turn out to be mistaken”.
The new data from Norwich adds an extra layer of skepticism to this sweeping hypothesis, informed in part by speculation. In their theory, Cochran and Harpending were trying to figure out why a key pillar of genetic evolution did not appear to apply to Jews. Natural selection, genetics theory had seemed to suggest, should flush dangerous DNA from the gene pool. What was the origins of these ‘Jewish disorders’, and why did they persist for centuries?
According to their theory, persecution and the historical tendency of Jews to define themselves as a “people” and to stay within a circumscribed community (sometimes imposed by hostile authorities in ghettoes) led to a high rate of Jewish intermarriage. That closed the gene pool, as Jews only married among themselves setting the stage for natural selection to do its work.
Loosely circumscribed Jewish communities Credit: Victor Center
Limits placed on the occupations available to Jews also played a part, according to their theory. Jews worked as traders before taking financial jobs made available by Christians who were forbidden by the Church from charging interest. By 1100, local registries listed most Ashkenazi Jews as lenders.
According to the theory, the smartest Jews made the most money, and the wealthiest families had the most surviving children. The genes of the most intelligent Jews spread most, slowly raising the average IQ of the entire group.
They concluded that this closing of the gene pool led to the rise of ‘Jewish genetic disorders, as deleterious genes were not filtered out by natural selection, as otherwise would be the case. Perhaps the mutations causing these diseases had some other, beneficial purpose that aided in their survival — like increased intelligence, they speculated? In other words, maybe the “faulty” genes, as Cochran later wrote, make Jews smarter.
PART II scheduled to run December 13
Patrick Whittle has a PhD in philosophy and is a freelance writer with a particular interest in the social and political implications of modern biological science. Follow him on his website patrickmichaelwhittle.com or on Twitter @WhittlePM
