A piece of scary implications , , ,
From issue: April 2007
By Charles Murray
Since its first issue in 1945, COMMENTARY has published hundreds of articles about Jews and Judaism. As one would expect, they cover just about every important aspect of the topic. But there is a lacuna, and not one involving some obscure bit of Judaica. COMMENTARY has never published a systematic discussion of one of the most obvious topics of all: the extravagant overrepresentation of Jews, relative to their numbers, in the top ranks of the arts, sciences, law, medicine, finance, entrepreneurship, and the media.
I have personal experience with the reluctance of Jews to talk about Jewish accomplishment—my co-author, the late Richard Herrnstein, gently resisted the paragraphs on Jewish IQ that I insisted on putting in The Bell Curve (1994). Both history and the contemporary revival of anti-Semitism in Europe make it easy to understand the reasons for that reluctance. But Jewish accomplishment constitutes a fascinating and important story. Recent scholarship is expanding our understanding of its origins.
And so this Scots-Irish Gentile from Iowa hereby undertakes to tell the story. I cover three topics: the timing and nature of Jewish accomplishment, focusing on the arts and sciences; elevated Jewish IQ as an explanation for that accomplishment; and current theories about how the Jews acquired their elevated IQ.
From 800 B.C.E. through the first millennium of the Common Era, we have just two examples of great Jewish accomplishment, and neither falls strictly within the realms of the arts or sciences. But what a pair they are. The first is the fully realized conceptualization of monotheism, expressed through one of the literary treasures of the world, the Hebrew Bible. It not only laid the foundation for three great religions but, as Thomas Cahill describes in The Gifts of the Jews (1998), introduced a way of looking at the meaning of human life and the nature of history that defines core elements of the modern sensibility. The second achievement is not often treated as a Jewish one but clearly is: Christian theology expressed through the New Testament, an accomplishment that has spilled into every aspect of Western civilization.
But religious literature is the exception. The Jews do not appear in the annals of philosophy, drama, visual art, mathematics, or the natural sciences during the eighteen centuries from the time of Homer through the first millennium C.E., when so much was happening in Greece, China, and South Asia. It is unclear to what extent this reflects a lack of activity or the lack of a readily available record. For example, only a handful of the scientists of the Middle Ages are mentioned in most histories of science, and none was a Jew. But when George Sarton put a high-powered lens to the Middle Ages in his monumental Introduction to the History of Science (1927-48), he found that 95 of the 626 known scientists working everywhere in the world from 1150 to 1300 were Jews—15 percent of the total, far out of proportion to the Jewish population.
As it happens, that same period overlaps with the life of the most famous Jewish philosopher of medieval times, Maimonides (1135–1204), and of others less well known, not to mention the Jewish poets, grammarians, religious thinkers, scholars, physicians, and courtiers of Spain in the "Golden Age," or the brilliant exegetes and rabbinical legislators of northern France and Germany. But this only exemplifies the difficulty of assessing Jewish intellectual activity in that period. Aside from Maimonides and a few others, these thinkers and artists did not perceptibly influence history or culture outside the confines of the Jewish world.
Generally speaking, this remained the case well into the Renaissance and beyond. When writing a book called Human Accomplishment (2003), I compiled inventories of "significant figures" in the arts and sciences, defined as people who are mentioned in at least half of the major histories of their respective fields. From 1200 to 1800, only seven Jews are among those significant figures, and only two were important enough to have names that are still widely recognized: Spinoza and Montaigne (whose mother was Jewish).
The sparse representation of Jews during the flowering of the European arts and sciences is not hard to explain. They were systematically excluded, both by legal restrictions on the occupations they could enter and by savage social discrimination. Then came legal emancipation, beginning in the late 1700's in a few countries and completed in Western Europe by the 1870's, and with it one of the most extraordinary stories of any ethnic group at any point in human history.
As soon as Jewish children born under legal emancipation had time to grow to adulthood, they started appearing in the first ranks of the arts and sciences. During the four decades from 1830 to 1870, when the first Jews to live under emancipation reached their forties, 16 significant Jewish figures appear. In the next four decades, from 1870 to 1910, the number jumps to 40. During the next four decades, 1910–1950, despite the contemporaneous devastation of European Jewry, the number of significant figures almost triples, to 114.
To get a sense of the density of accomplishment these numbers represent, I will focus on 1870 onward, after legal emancipation had been achieved throughout Central and Western Europe. How does the actual number of significant figures compare to what would be expected given the Jewish proportion of the European and North American population? From 1870 to 1950, Jewish representation in literature was four times the number one would expect. In music, five times. In the visual arts, five times. In biology, eight times. In chemistry, six times. In physics, nine times. In mathematics, twelve times. In philosophy, fourteen times.
Disproportionate Jewish accomplishment in the arts and sciences continues to this day. My inventories end with 1950, but many other measures are available, of which the best known is the Nobel Prize. In the first half of the 20th century, despite pervasive and continuing social discrimination against Jews throughout the Western world, despite the retraction of legal rights, and despite the Holocaust, Jews won 14 percent of Nobel Prizes in literature, chemistry, physics, and medicine/physiology. In the second half of the 20th century, when Nobel Prizes began to be awarded to people from all over the world, that figure rose to 29 percent. So far, in the 21st century, it has been 32 percent. Jews constitute about two-tenths of one percent of the world's population. You do the math.
What accounts for this remarkable record? A full answer must call on many characteristics of Jewish culture, but intelligence has to be at the center of the answer. Jews have been found to have an unusually high mean intelligence as measured by IQ tests since the first Jewish samples were tested. (The widely repeated story that Jewish immigrants to this country in the early 20th century tested low on IQ is a canard.) Exactly how high has been difficult to pin down, because Jewish sub-samples in the available surveys are seldom perfectly representative. But it is currently accepted that the mean is somewhere in the range of 107 to 115, with 110 being a plausible compromise.
The IQ mean for the American population is "normed" to be 100, with a standard deviation of 15. If the Jewish mean is 110, then the mathematics of the normal distribution says that the average Jew is at the 75th percentile. Underlying that mean in overall IQ is a consistent pattern on IQ subtests: Jews are only about average on the subtests measuring visuo-spatial skills, but extremely high on subtests that measure verbal and reasoning skills.
A group's mean intelligence is important in explaining outcomes such as mean educational attainment or mean income. The key indicator for predicting exceptional accomplishment (like winning a Nobel Prize) is the incidence of exceptional intelligence. Consider an IQ score of 140 or higher, denoting the level of intelligence that can permit people to excel in fields like theoretical physics and pure mathematics. If the mean Jewish IQ is 110 and the standard deviation is 15, then the proportion of Jews with IQ's of 140 or higher is somewhere around six times the proportion of everyone else.
The imbalance continues to increase for still higher IQ's. New York City's public-school system used to administer a pencil-and-paper IQ test to its entire school population. In 1954, a psychologist used those test results to identify all 28 children in the New York public-school system with measured IQ's of 170 or higher. Of those 28, 24 were Jews.
Exceptional intelligence is not enough to explain exceptional accomplishment. Qualities such as imagination, ambition, perseverance, and curiosity are decisive in separating the merely smart from the highly productive. The role of intelligence is nicely expressed in an analogy suggested to me years ago by the sociologist Steven Goldberg: intelligence plays the same role in an intellectually demanding task that weight plays in the performance of NFL offensive tackles. The heaviest offensive tackle is not necessarily the best. Indeed, the correlation between weight and performance among NFL offensive tackles is probably quite low. But they all weigh more than 300 pounds.
So with intelligence. The other things count, but you must be very smart to have even a chance of achieving great work. A randomly selected Jew has a higher probability of possessing that level of intelligence than a randomly selected member of any other ethnic or national group, by far.
Nothing that I have presented up to this point is scientifically controversial. The profile of disproportionately high Jewish accomplishment in the arts and sciences since the 18th century, the reality of elevated Jewish IQ, and the connection between the two are not to be denied by means of data. And so we come to the great question: how and when did this elevated Jewish IQ come about? Here, the discussion must become speculative. Geneticists and historians are still assembling the pieces of the explanation, and there is much room for disagreement.
I begin with the assumption that elevated Jewish intelligence is grounded in genetics. It is no longer seriously disputed that intelligence in Homo sapiens is substantially heritable. In the last two decades, it has also been established that obvious environmental factors such as high income, books in the house, and parental reading to children are not as potent as one might expect. A "good enough" environment is important for the nurture of intellectual potential, but the requirements for "good enough" are not high. Even the very best home environments add only a few points, if that, to a merely okay environment. It is also known that children adopted at birth do not achieve the IQ's predicted by their parents' IQ.
To put it another way, we have good reason to think that Gentile children raised in Jewish families do not acquire Jewish intelligence. Hence my view that something in the genes explains elevated Jewish IQ. That conclusion is not logically necessary but, given what we know about heritability and environmental effects on intelligence in humans as a species, it is extremely plausible.
Two potential explanations for a Jewish gene pool favoring high intelligence are so obvious that many people assume they must be true: winnowing by persecution (only the smartest Jews either survived or remained Jews) and marrying for brains (scholars and children of scholars were socially desirable spouses). I too think that both of these must have played some role, but how much of a role is open to question.
In the case of winnowing through persecution, the logic cuts both ways. Yes, those who remained faithful during the many persecutions of the Jews were self-selected for commitment to Judaism, and the role of scholarship in that commitment probably means that intelligence was one of the factors in self-selection. The foresight that goes with intelligence might also have had some survival value (as in anticipating pogroms), though it is not obvious that its effect would be large enough to explain much.
But once the Cossacks are sweeping through town, the kind of intelligence that leads to business success or rabbinical acumen is no help at all. On the contrary, the most successful people could easily have become the most likely to be killed, by virtue of being more visible and the targets of greater envy. Furthermore, other groups, such as the Gypsies, have been persecuted for centuries without developing elevated intelligence. Considered closely, the winnowing-by-persecution logic is not as compelling as it may first appear.
What of the marrying-for-brains theory? "A man should sell all he possesses in order to marry the daughter of a scholar, as well as to marry his daughter to a scholar," advises the Talmud (Pesahim 49a), and scholarship did in fact have social cachet within many Jewish communities before (and after) emancipation. The combination could have been potent: by marrying the children of scholars to the children of successful merchants, Jews were in effect joining those selected for abstract reasoning ability with those selected for practical intelligence.
Once again, however, it is difficult to be more specific about how much effect this might have had. Arguments have been advanced that rich merchants were in fact often reluctant to entrust their daughters to penniless and unworldly scholars. Nor is it clear that the fertility rate of scholars, or their numbers, were high enough to account for a major effect on intelligence. The attractiveness of brains in prospective marriage partners surely played some role but, once again, the data for assessing how much have not been assembled.
Against this backdrop of uncertainty, a data-driven theory for explaining elevated Jewish IQ appeared in 2006 in the Journal of Biosocial Science. In an article entitled "Natural History of Ashkenazi Intelligence," Gregory Cochran (a physicist) and Jason Hardy and Henry Harpending (anthropologists) contend that elevated Jewish IQ is confined to the Ashkenazi Jews of northern and central Europe, and developed from the Middle Ages onward, primarily from 800 to 1600 C.E.
In the analysis of these authors, the key factor explaining elevated Jewish intelligence is occupational selection. From the time Jews became established north of the Pyrenees-Balkans line, around 800 C.E ., they were in most places and at most times restricted to occupations involving sales, finance, and trade. Economic success in all of these occupations is far more highly selected for intelligence than success in the chief occupation of non-Jews: namely, farming. Economic success is in turn related to reproductive success, because higher income means lower infant mortality, better nutrition, and, more generally, reproductive "fitness." Over time, increased fitness among the successful leads to strong selection for the cognitive and psychological traits that produce that fitness, intensified when there is a low inward gene flow from other populations—as was the case with Ashkenazim.
Sephardi and Oriental Jews—i.e., those from the Iberian peninsula, the Mediterranean littoral, and the Islamic East—were also engaged in urban occupations during the same centuries. But the authors cite evidence that, as a rule, they were less concentrated in occupations that selected for IQ and instead more commonly worked in craft trades. Thus, elevated intelligence did not develop among Sephardi and Oriental Jews—as manifested by contemporary test results in Israel that show the IQ's of non-European Jews to be roughly similar to the IQ's of Gentiles.
The three authors conclude this part of their argument with an elegant corollary that matches the known test profiles of today's Ashkenazim with the historical experience of their ancestors:
The suggested selective process explains the pattern of mental abilities in Ashkenazi Jews: high verbal and mathematical ability but relatively low spatio-visual ability. Verbal and mathematical talent helped medieval businessmen succeed, while spatio-visual abilities were irrelevant.
The rest of their presentation is a lengthy and technical discussion of the genetics of selection for IQ, indirect evidence linking elevated Jewish IQ with a variety of genetically based diseases found among Ashkenazim, and evidence that most of these selection effects have occurred within the last 1,200 years.
No one has yet presented an alternative to the Cochran-Hardy-Harpending theory that can match it for documentation. But, as someone who suspects that elevated Jewish intelligence was (a) not confined to Ashkenazim and (b) antedates the Middle Ages, I will outline the strands of an alternative explanation that should be explored.
It begins with evidence that Jews who remained in the Islamic world exhibited unusually high levels of accomplishment as of the beginning of the second millennium. The hardest evidence is Sarton's enumeration of scientists mentioned earlier, of whom 15 percent were Jews. These were not Ashkenazim in northern Europe, where Jews were still largely excluded from the world of scientific scholarship, but Sephardim in the Iberian peninsula, in Baghdad, and in other Islamic centers of learning. I have also mentioned the more diffuse cultural evidence from Spain, where, under both Muslim and Christian rule, Jews attained eminent positions in the professions, commerce, and government as well as in elite literary and intellectual circles.
After being expelled from Spain at the end of the 15th century, Sephardi Jews rose to distinction in many of the countries where they settled. Some economic historians have traced the decline of Spain after 1500, and the subsequent rise of the Netherlands, in part to the Sephardi commercial talent that was transferred from the one to the other. Centuries later, in England, one could point to such Sephardi eminences as Benjamin Disraeli and the economist David Ricardo.
In sum, I propose that a strong case could be assembled that Jews everywhere had unusually high intellectual resources that manifested themselves outside of Ashkenaz and well before the period when non-rabbinic Ashkenazi accomplishment manifested itself.