Photo: Jill Greenberg

This story begins, as it inevitably must, in the Old Country.

At some point during the tenth century, a group of Jews abandoned the lush hills of Lucca, Italy, and—at the invitation of Charlemagne—headed for the severer climes of the Rhineland and Northern France. These Jews didn’t have a name for themselves, at first. They were tied together mostly by kinship. But ultimately, they became known as Ashkenazim, a variation on the Hebrew word for one of Noah’s grandsons.

In some ways, life was good for the Jews in this strange new place. They’d been lured there on favorable terms, with promises of physical protection, peaceful travel, and the ability to adjudicate their own quarrels. (The charter of Henry IV, dated 1090, includes this assurance: “If anyone shall wound a Jew, but not mortally, he shall pay one pound of gold … If he is unable to pay the prescribed amount … his eyes will be put out and his right hand cut off.”) But in other ways, life was difficult. The Ashkenazim couldn’t own land. They were banned from the guilds. They were heavily taxed.

Yet the Ashkenazim did very well, in spite of these constraints, because they found an ingenious way to adapt to their new environment that didn’t rely on physical labor. What they noticed, as they set up their towns, located mainly at the crossroads of trade routes, was that there was no one around to lend money.

So there it was: a demand and a new supplier. Because of the Christian prohibition against usury, Jews found themselves a financially indispensable place in their new home, extending loans to peasants, tradesmen, knights, courtiers, even the occasional monastery. The records from these days are scarce. But where they exist, they are often startling. In 1270, for example, 80 percent of the 228 adult Jewish males in Perpignan, France, made their living lending money to their Gentile neighbors, according to Marcus Arkin’s Aspects of Jewish Economic History. One of the most prolific was a rabbi. Two others were identified, in the notarial records, as “poets.”

Success at money-lending required a different set of skills than farming or any of the traditional trades. Some, surely, were social: cultivating connections, winning over trust (or maybe bullying your way there, Shylock’s awful pound of flesh). It probably required some aggression, because the field was competitive, with Jews suffering so few professional options. But it also required cognitive skills, or something my generation would call numeracy—a fluency in mathematics, a dexterity with numbers—and my grandmother’s generation would call “a head for figures.” If you were Jewish in Perpignan in 1270, and you didn’t have a head for figures, you didn’t stand much of a chance.

Numeracy, literacy, critical reasoning: For millennia, these have been the currency of Jewish culture, the stuff of Talmudic study, immigrant success, and Borscht Belt punch lines. Two Jews, three opinions … Keep practicing, you’ll thank me later … Q: When does a Jewish fetus become a human? A: When it graduates from medical school.

Of course, there’s another side to this shining coin. Jewish cleverness has also been an enduring feature of anti-Semitic paranoia. In the sixteenth century, Martin Luther said Jewish doctors were so smart they could develop a poison that could kill Christians in a single day—or any other time period of their choosing (and four centuries later, Pravda suggested Jewish doctors were spies sent to kill Stalin). After the calamities of September 11, one of the creepier conspiracy theories to whip through the Muslim world was the idea that only Jews were cunning enough to have pulled off the hijackings.

Last summer, Henry Harpending, an evolutionary anthropologist at the University of Utah, and Gregory Cochran, an independent scholar with a flair for controversy, skipped cheerfully into the center of this minefield. The two shopped around a paper that tried to establish a genetic argument for the fabled intelligence of Jews. It contended that the diseases most commonly found in Ashkenazim—particularly the lysosomal storage diseases, like Tay-Sachs—were likely connected to and, indeed, in some sense responsible for outsize intellectual achievement in Ashkenazi Jews. The paper contained references, but no footnotes. It was not written in the genteel, dispassionate voice common to scientific inquiries but as a polemic. Its science was mainly conjecture. Most American academics expected the thing to drop like a stone.

It didn’t. The Journal of Biosocial Science, published by Cambridge University Press, posted it online and agreed to run it in its bi-monthly periodical sometime in 2006. The New York Times, The Economist, and several Jewish publications risked their reputations to legitimize it. Today, the paper has a lively presence on the Internet—type “Ashkenazi” into Google and the first hit is the Wikipedia entry, where the article gets pride of place.

Photo: From top, courtesy of Henry Harpending; courtesy of Gregory Cochran

Ascribing an ethnic or racial explanation to any trait more ambiguous than skin color is by definition a dangerous idea, the kind of notion that can seep into the political arena with disastrous consequences. Institutionalized racism has always found sanction in the scientific community, from eminent biologist Louis Agassiz’s racial typologies justifying slavery in the 1850s, to the Nazi scientists’ depraved use of calipers to establish Jewish inferiority, to psychologist Arthur Jensen’s call in the sixties to stop funding Head Start because most of its poor, black recipients were intrinsically uncoachable.

We may consider ourselves the products of a new, more enlightened age, and scientists may carry on with more sensitivity than they did in the past. Yet to invoke the genome as an explanation for anything more complicated than illness or the most superficial traits (like skin color) is still considered taboo, as Harvard president Larry Summers discovered when he suggested the reason for so few female math and science professors might lurk in scribbles of feminine DNA (rather than, say, the hostile climes of the classroom, the diminished expectations of women’s parents, or a curious cultural receptivity to Pamela Anderson’s charms).

For this reason, and the fact that it did not meet the standards of traditional scientific scholarship, Harpending and Cochran’s paper attracted a barrage of criticism from mainstream geneticists, historians, and social scientists.

“It’s bad science—not because it’s provocative, but because it’s bad genetics and bad epidemiology,” says Harry Ostrer, head of NYU’s human-genetics program.

“I see no positive impact from this,” says Neil Risch, one of the few geneticists who’s dipped his oar into the treacherous waters of race and genetics. “When the guys at the University of Utah said they’d discovered cold fusion, did that have a positive impact?”

“I’d actually call the study bullshit,” says Sander Gilman, a historian at Emory University, “if I didn’t feel its idea were so insulting.”

Cochran mirthfully bats their complaints away. “I don’t see what the big deal is here,” he says when I reach him at his New Mexico home. “I haven’t actually told people how to make a hydrogen bomb out of baking soda in their garages.”

But there’s no question that Cochran and Harpending knew what they were doing. They were advancing a theory with a patina of sexiness and political incorrectness, one that would generate a good deal of discussion. And that it did. Some of that discussion was positive, and some was not, as one might expect. That’s always the problem with theories that exploit stereotypes—they’re titillating, sure, but also handy refuges for the intellectually lazy. The trick is not to harden and grow cold as we turn backward, as sure as Lot’s wife.

“Albert Einstein is reputed to have said that ‘Things should be described as simply as possible, but no simpler,’ ” reads the first sentence of Natural History of Ashkenazi Intelligence. “The same principle must be invoked in explaining Einstein himself.” The authors, clearly, have no fear of getting personal. Einstein, they seem to be saying. Need we say more? The man whose very name is a shorthand for genius was an Ashkenazi Jew.

The world’s proliferation of Einsteins—well, maybe not Einsteins exactly, but distinguished Jewish thinkers, particularly in math and the sciences—form the stark, quantifiable basis for Cochran and Harpending’s hypothesis. Though Jews make up a mere 0.25 percent of the world’s population and a mere 3 percent of the United States’, they account, according to their paper, for 27 percent of all American Nobel Prize winners, 25 percent of all ACM Turing Award winners for computer science, and 50 percent of the globe’s chess champions. (What the paper doesn’t say is that these numbers seem to be tallied for optimum Jewishness, counting as Jews those who have as few as one Jewish grandparent to claim; it also wrongly assumes these winners are all Ashkenazim. But still.) Cochran and Harpending also cite studies claiming that Ashkenazim have the highest IQ of any ethnic group for which there’s reliable data, perhaps as much as a full standard deviation above the general European average, which means, at the far end of the spectrum, that 23 per thousand Ashkenazim have an IQ over 140, as opposed to 4 per thousand Northern Europeans.

Reading these numbers, I was reminded of a story a friend once told me about a peer of his at Cambridge who wearily dismissed the intellect of another student with a five-word declaration: “Just your average Jewish genius.”

Most social scientists—and biological scientists, for that matter—would argue that a complex combination of culture, history, and religious tradition has been responsible for the steady, metronomic production of average Jewish geniuses. Cochran and Harpending make a different case.

Their reasoning is straightforward enough: If the gene mutations responsible for diseases in Ashkenazim didn’t confer some evolutionary selective advantage, they wouldn’t persist. Cochran and Harpending liken these defective genes to the genes in Africans that often deform hemoglobin. Carrying one copy of the gene, most research suggests, helps ward off malaria—surely an adaptive advantage. Two copies, however, cause sickle-cell anemia.

Cochran and Harpending reasoned the same must be true of the genes that cause illness among Ashkenazi Jews, particularly the four that cause mutations in the enzymes responsible for breaking down fats: Tay-Sachs, Niemann-Pick, Gaucher disease, and mucolipidosis type IV. Two copies cause devastating illness, but one, they speculate, mutely aids the carrier.

How? By enhancing intelligence. Without this extra edge, they hypothesize, the Ashkenazim would never have survived. The Jews “experienced unusual selective pressures that were likely to have favored increased intelligence,” they say. “Their jobs were cognitively demanding, since they were essentially restricted to entrepreneurial and managerial roles as financiers, estate managers, tax farmers, and merchants. These are jobs that people with an IQ below 100 essentially cannot do.”

“I have a stack of books, like four feet high, on all metabolic diseases,” Cochran tells me. “And the four sphingolipid diseases affecting Ashkenazi Jews”—the ones he and Harpending believe enhance intelligence—“are all in the same chapter. That’s like one in 100,000 odds. People could say it’s chance, I suppose—in the same way it’s chance that 27 percent of all of those guys go to Stockholm every year.”

There’s scant physical evidence for this assumption. But what the authors found was intriguing. Among the papers they unearthed were studies by Steven Walkley, a neuroscientist at Albert Einstein College of Medicine, that showed growth of additional dendrites in the tissues of humans and cats with Tay-Sachs and Niemann-Pick. They also cite a 1995 study in the Journal of Biological Chemistry that shows increased neural growth in the brains of rats with Gaucher disease. The authors decided to contact Ari Zimran, the head of the Gaucher Clinic at the Shaare Zedek Medical Center in Jerusalem. It turns out that 81 of his 255 working-age patients have jobs that require, by the author’s estimates, an IQ of at least 120. Twenty-three are engineers, and fourteen are scientists—a number that, if it were consistent with the Israeli workforce, should be just six.

Yet there are many who’d find a very different way of explaining the intelligence of these patients. They wouldn’t invoke their extra dendrites. They’d invoke their mothers. To say that the Jews have a history of emphasizing scholarship is not just the fantasy of ethnic chauvinists and Woody Allen fans. To look at a single page of the Talmud is to understand this, with its main text at the center, its generations of rabbis arguing around the rim. The dialectic and critical reasoning are at its core.

Growing up, most children in Jewish households are at least vaguely aware of their intellectual aristocracy—who do you think was counting all those Nobel Prize winners? The Swedes?—and if it’s not the intellectuals they’re aware of, it’s the high-achieving Jews, the ones who killed on Dick Cavett, played lead guitar, helmed the Starship Enterprise. (The one season I attended Sunday school, one of my first assignments was to find the name of a Jewish celebrity; when I returned the following week with the name of Beverly Sills, rather than Gene Simmons, my teacher didn’t find it the least bit strange.) All minorities have their private halls of fame, of course, but it was a Jew, Adam Sandler, who took this obsessive curatorial tendency and set it to music. “David Lee Roth lights the menorah / So do James Caan, Kirk Douglas, and the late Dinah Shore-ah … ”

It’s staggering what an emphasis on scholarship, both secular and religious, combined with a history of relentless displacement will do. One could argue it’s a near-certain recipe for achievement. Just last month, Sherwin Nuland, author of How We Die, wrote a meticulous, almost pointillist essay for The New Republic explaining why Jewish doctors have been held in high esteem for centuries. (The title of the article: “My Son, the Doctor.”) He notes that physical healing has always been privileged by Jewish scripture, and therefore became the province of learned rabbis, the apotheosis of whom was Maimonides. If the Jews were expelled from a particular country, as they so often were, they could take their profession with them—medicine was divinely portable.

From there, Nuland draws on the work of John Efron, a historian at the University of California at Berkeley, pointing out that once universities opened their doors to Jews, much of the Jewish emphasis on scholarship shifted from the religious to the secular, partly as a result of their tremendous desire for social respectability. At the fin de siècle, for example, Jews made up a mere 1 percent of the German population, but they made up 50 percent of all the doctors in Berlin and 60 percent of all the doctors in Vienna. “It had to do with emerging from the ghetto,” says Efron, author of Medicine and the German Jews: A History. “There were enormous social pressures to succeed—part of the emancipation process was to show that Jews were good Europeans, good Austrians, and medicine was a universal, non-parochial science, where the barriers to entry were low but the prestige was enormously high. It’s the same pattern you’re seeing in the United States today, if you have a look at medical-school acceptances: There are much larger numbers of Asian and Indian students.” Numbers from the American Association of Medical Colleges bear this out: Today, 18 percent of all med students are Asian, as opposed to 6 percent just a dozen years ago.

“I have always believed that the smartest people in the world are Asians,” declares Ed Koch, former mayor of New York (and, let’s face it, a pretty smart Ashkenazi Jew). “If you look at the special schools in New York City, they have so many. I think Stuyvesant’s 40 percent Asian now, and Bronx Science is 50”—actually, 53 and 49 percent—“so this paper is something I question.”

Jews have long debated the origin and nature of intelligence. In Kaddish, his beautiful book of aphorisms and ruminations about the rite of mourning, Leon Wieseltier notes that Rabbi Akiva postulated in the second century that sons inherit not just wealth, beauty, and strength from their fathers, but wisdom. Centuries later, Maimonides came to the opposite conclusion: It’s “great exertion” that makes us who we are. To attribute it to anything in our blood would trivialize our own agency, our hard work, our humanity. Wieseltier can’t even countenance another point of view. “The important question is, even if there is an Ashkenazi gene, what does it explain and what does it not explain?” he asks, when I reach him by phone. “The idea that it explains intellectuality seems empirically and philosophically spurious. The world is riddled—riddled!—with dumb Ashkenazi Jews, so it’s empirically false, and it’s philosophically spurious because it flies in the face of human freedom and the belief in human freedom.”

He thinks. “We’re living in a new golden age of scientism—the idea that there are scientific answers to all human questions,” he says. “People are so rattled by the speed and complexity of their lives that they need rock-solid certainty. They cannot bear to live inconclusively. Religion provides one definitive answer; science provides another. The important thing for most people is to feel that the way they live is an inevitable outcome.”

“I probably have a lot to say about this,” he concludes, “because I’m an Ashkenazi. So I must be really smart.”

Harpending and Cochran are hardly the first scientists to suggest that the diseases of the Ashkenazim are the product of genetic selection. Until fairly recently, many geneticists believed these mutations may have helped protect Jews from tuberculosis, because the disease so frequently surfaced in ghettos, though no one has been able to show how these mutations protected Jews—or why neighboring non-Jewish populations didn’t develop the same immunity.

If geneticists are disinclined to believe a trait is the result of natural selection, they attribute it instead to something called genetic drift, a process by which a mutation, for some random reason, evolves in one population but not in another. The smaller the population, the more glaring this mutation will seem. Geographic isolation, for instance, can explain radical genetic differences—if two groups evolve in separate places with little intermingling, different mutations are bound to pop up and spread in each. Natural disasters are another explanation—a rock slide could kill off a species of purple petunias, say. Or—in the case of Jews—one of the founders of a small settlement has a lot of children, and these children have lots of children. What the founder doesn’t know is that he or she has a gene mutation, like the one for Tay-Sachs. It takes hold and spreads, like an epidemic. (Geneticists call this “the founder effect.”)

“Ashkenazi neurological diseases are hints of ways in which one could supercharge intelligence, so it seems likely we could develop pharmaceutical agents that had similar effects.”

The problem with this theory, as Cochran and Harpending rather forcefully argue using mathematical models and a long disquisition about medieval Jewish economic history (starting from the expulsion of the Jews by King Dagobert of the Franks in 629), is that Tay-Sachs is just one of four sphingolipid diseases common to Jews, which seems like a rather unlikely coincidence. It suggests they all evolved for a reason, a similar reason. How could random mutations account for such a closely related cluster of ailments?

“That’s one of the ways this paper is actually strong,” says Sheila Rothman, a Columbia professor of public health who specializes in questions about genetics and group identity. “Geneticists don’t have a great grasp of Jewish history. They often tend to cite each other. Sometimes they cite themselves.”

It’s not just social scientists who concede this part of the paper is strong. So, too, do many mainstream geneticists, who’ve never been entirely comfortable with the theory of genetic drift to explain so many interrelated diseases among Jews.

“If these genes were shuffling randomly,” says Gregory Pastores, director of the neurogenetics unit at NYU, “then why is it that we see the clustering of four diseases in Jews—Gaucher, Niemann-Pick, mucolipidosis type IV, and Tay-Sachs—when the genes are in different chromosomes entirely? They’re not even next to one another.”

But this doesn’t mean that Pastores buys the message of the paper, and neither do most of his colleagues. Ostrer, from NYU, points out what he believes is a major flaw: The authors assume Jews are selected for sphingolipid diseases, and not for some other gene that may happen to be passed along with these diseases. “Blocks of the genome are inherited together,” he explains. “They’re saying heterozygotes carrying these sphingolipid mutations are smarter. Fine. But who’s to say it’s that gene and not the gene next door? Or down the street?”

Furthermore, the authors’ hypothesis that what’s being selected for is intelligence is a sexy guess, but it’s based on almost nothing concrete—just a handful of smart Gaucher patients, some extra dendrites in cats, and a rat. “Jews have been accused of being frugal, cheap, aggressive,” says Neil Risch. “There’s a clear survival advantage to those traits too. Why not pick on those?”

Risch is a big believer in genetic drift. He thinks the large number of mutations in Jews is random, coincidental, and has no causal relationship with the number of children they’ve had or why they’ve survived. He points out Ashkenazim are prone to other illnesses besides lysosomal storage diseases (such as clotting disorders and breast cancer). Anyway, what’s so unique about Jews? Finns are prone to at least twenty diseases, as are French Canadians, Costa Ricans, Louisiana Acadians, the Amish, and European Gypsies. The Gypsies have interrelated diseases too, just like the Jews have interrelated sphingolipid disorders.

Risch is underwhelmed. “This is like saying, ‘Because Europeans have a high rate of cystic fibrosis, hemochromatosis, and Crohn’s disease, the genes for those disorders must cause great ability to play tennis,’ ” he says. “And then the authors would come up with some elaborate theory about how those particular mutations are involved in hand-eye coordination, which allows for better retrieval of volleys.”

Yet here’s the irony: During the past year, the taboos surrounding the genetics of race and ethnicity have been significantly eroded, in no small part because of the efforts of Risch. A population geneticist at the University of California at San Francisco, a fiercely independent thinker, a fun gossip, and a liberal Jew, he published a paper in the American Journal of Human Genetics in February that rather boldly claimed that the races we claimed to be almost always corresponded with our continents of ancestry. It seemed to represent the consensus view that’s slowly emerging among geneticists. Many have now stopped quarreling with the same vigor about whether race is or is not a genetic fact.

“I am not sure that most geneticists have agreed to ‘races’ per se,” says Ostrer. “But continental groups or clusters, yes.” To deny these clusters, he says, would be folly; it tells us to willfully ignore what all of us can see—that people look different all over the world. He quotes me a line from Jews: A Study in Race and Environment, written by his NYU predecessor, Maurice Fishberg: “One can pick out a Jew from among a thousand non-Jews without difficulty.” Ostrer is now writing a book himself, about genetics and Jewish history. He has decided to call the first chapter “Looking Jewish.”

“There’s no doubt their paper is polemical,” says David Goldstein, director of the Center for Population Genomics and Pharmacogenetics at Duke University. “But just because it’s polemical doesn’t mean I’d be dismissive of everything they had to say. I think their paper’s interesting.”

Goldstein, in fact, seems to rather appreciate its Zeitgeist. “Until recently, most human geneticists almost … disalloweddiscussion about genetic differences among racial and ethnic groups,” he says. “Really. So many awful things had been done with genetic research in this last century that they developed a policy of ‘Just say no.’ But there’s actually a lot of difference between groups, when you consider there are 10 million polymorphic sites on the genome. So it’s not scientifically sound to rule out the possibility of differences corresponding to our geographic and ethnic heritages. It overlooks the basic point: The genome is just a huge place.”

“If I had to choose between Jewish genes and Jewish mothers,” Goldstein hastens to add, “I’d choose Jewish mothers.” (He has both.) “But I would like us to carry out research in a way that doesn’t imply that we have anything to be afraid of. That’s what upsets me about the way this work has been approached in the past.”

Using the notion of race, for example, has proved highly useful in medicine. Today, if you’re an ambitious young geneticist, the world’s awash in money to study racial difference and disease. It’s even encouraged by statute, thanks to the Minority Health Disparities Act of 2000. This summer, the National Institutes of Health announced it was exploring links between African-Americans and elevated rates of prostate cancer; this spring, NitroMed introduced BiDil to reduce heart disease in African-Americans.

“Historically, in medicine, white males have been the subjects of study,” says Risch. “But you can’t always apply to women and minorities [lessons] from them. You need to be inclusive. So while I’m always afraid people will misuse information about genetic differences, this is a positive development.”

Just because pharmaceutical companies are developing race-specific drugs, however, doesn’t mean race is the most useful way to parse genetic differences. The fact remains that there’s more diversity within racial groups than between them. What does “black” mean when discussing the 11,700,000-square-mile expanse of Africa? There are Pygmies and Nigerians, Zulus and Ethiopians. What, precisely, is a Mexican? Or—for that matter—a Semite?

“BiDil is more effective for some, rather than all, African-American hypertensives,” says Ostrer. “Race, in this context, should always be used as an interim measure to see us through a period of ignorance,” agrees Goldstein. “Once we know the underlying genetic or environmental factors that influence individual responses, you consider those directly and ignore race.”

Talk to most geneticists, and they’ll say that it’s a combination of genetics and environment that inevitably makes us who we are—attempts to link specific behaviors, aptitudes, and weaknesses to genes and genes alone almost always come up short. Lynn Jorde, professor of genetics at the University of Utah School of Medicine, gives but one example: For a while, it was assumed that a particular variant of monoamine oxidase caused antisocial behavior. Then several thousand children in New Zealand with this variant were followed for a period of more than twenty years. Researchers found that their subjects misbehaved only if they’d been abused as children—if they hadn’t, there was none. “We’ll probably find that there are genes that influence behavior,” says Jorde. “But I’m quite certain we won’t find genes that determine behavior.”

Risch noted something similar in Nature Genetics last year: Until recently, a famous study seemed to suggest that Asian children were more likely than Europeans to have absolute pitch. Then along came another study, this time showing that absolute pitch is most likely to manifest itself only if children take music lessons before the age of 6. No one in the first study had bothered to ask whether their Asian subjects were exposed earlier to music than their European counterparts.

And that’s just absolute pitch, easily measurable. Intelligence isn’t even possible to define, except maybe in the sense that Justice Potter Stewart famously said of porn: He knew it when he saw it. Intelligence is almost impossible to model in animals. How do you create a brainy Jewish mouse? (Replicate Michael Eisner?) There’s book-smart and street-smart; numbers-smart and letters-smart. Matisse dreamed in paint, and Nabokov did magic tricks with words, but could either of them do multivariable calculus? How about calculate the tip on a bar bill?

“The problem is with phenotype,” says David Rothman, a Columbia historian (and Sheila’s husband). “Take schizophrenia. There’s four kinds listed in the Diagnostic and Statistical Manual of Mental Disorders. Or take alcoholism. The phenotypes are also varied—there’s weekend bingers, hard drinkers, occasional bingers. Depression comes in many phenotypes. I don’t know where to begin with shyness. So intelligence? I’m baffled.”

“More important,” he adds, “I don’t know where they get the idea that mercantile life and high IQs go together. I wouldn’t mind IQ-testing the bulls of Wall Street to find this out.”

In the 1860s, Francis Galton, a cousin of Charles Darwin and father of eugenics, argued that Protestants were smarter than Catholics because they let their smart offspring reproduce, rather than shipping them off to monasteries. The idea didn’t hold up too well over time. In the early part of the twentieth century, the mathematician Norbert Wiener suggested Jews were smarter because the daughters of wealthy Jewish men were married off to scholarly rabbis, who went on to have more children. Then Lewis S. Feuer, a sociologist, came along and showed that wealthy Jews married other wealthy Jews. “These were Fiddler on the Roof fantasies, a myth created by people in New York who romanticized the shtetl,” says Sander Gilman. “The shtetls were horrible places. Do you think the man who wrote Tevye’s story did it from a crummy little shtetl? No! He was sitting in the south of France on the Riviera. He’s no fool.”

“This study is putting forward one of these arguments you hear regularly but with new window dressing,” Gilman says. “Today, that dressing is genetics. A hundred years ago, it was vitamins—as soon as they were discovered, everything was explained by a vitamin deficiency. Cancer. Schizophrenia. Hair loss.” He pauses. “Okay, not hair loss. I made that up. But you see my point.”

So who, exactly, are these people who’ve caused such a fuss? Harpending is certainly the more conventional of the two: a tenured professor, a respected population geneticist, and a member of the National Academy of Sciences, an organization to which few slouches are accidentally admitted. When I speak to him on the phone, he sounds good-humored, cheerfully indifferent to academic niceties, and slightly bored. “I wouldn’t think of letting a grad student work on this,” he says. “I’m very senior. I don’t live off grants. If I were running a lab, dependent on funding from the NIH, this would be the kiss of death.”

What do his colleagues think of his work?

“They think it’s probably right,” he says. “But in public, their only reaction is a primate fear grimace.”

But is that really the case? I ask Jorde what his colleagues in the Utah genetics lab thought of Harpending’s study. He answers with extreme tact. “Most of us work on very different kinds of things,” he says. “It’s really peripheral to our kinds of interests.”

Cochran, however, is another matter. He’s a bit of a wild card, a fellow who has developed a knack for pushing unorthodox notions under the aegis of more mainstream intellectual patrons. In the late nineties, he teamed up with a biologist at Amherst, Paul Ewald, to explore the possibility that many of the diseases we consider intractable are mere germs, which ultimately made them the subjects of a cover story in The Atlantic Monthly in 1999. (Their idea is less crazy than one might think; for years, surgeons removed stomachs to get rid of ulcers, only to discover they were caused by … a germ.)

Cochran’s latest kick, though, is population genetics. Although Natural History of Ashkenazi Intelligence is written with a modicum of academic restraint, his independent essays, posted online, are much more freewheeling, and they betray a much more unsettling agenda: “[I]f this is what I think it is,” he writes, in an essay called “Overclocking,” the term programmers use to describe supercharging a computer’s brain capacity by weakening it, “all these Ashkenazi neurological diseases are hints of ways in which one could supercharge intelligence … so it seems likely that we could—if we wanted to—develop pharmaceutical agents that had similar effects.”

To Cochran, in other words, Jews are the smart mice of history.

The Times, The Economist, and every other media outlet somehow missed this when they first reported that Cochran and Harpending’s paper had been accepted for publication. Or at least they chose not to report it. Nor did they choose to report another interesting fact: The Journal of Biosocial Science, though part of a family of Cambridge University Press publications, went by the name The Eugenics Review until 1968.

“This guy is not some proto-Zionist,” says David Rothman. It was Rothman’s researcher, Nate Drummond, who shrewdly unearthed this information about Cochran. “What’s driving him, as you read this, is bioengineering, not philo-Semitism.”

So the plot thickens. At one point, I ask Cochran if he’s serious about studying Jews in order to create “pharmaceutical agents” for mankind’s general intellectual enhancement. Has he thought about taking this idea to pharmaceutical companies?

“I’ve thought about it halfway seriously,” he says, hesitating a bit. “I’m probably not supposed to say. Because let’s say it happens. Come patent time, I’ll have told people.”

So. Is this study good for the Jews? I talk to Abe Foxman, legendary head of the Anti-Defamation League, whose life’s mission is the pristine upkeep of the Jewish reputation. His answer surprises me. “If it’s a genetic condition,” he says, “it’s not for us to embrace or reject. It is what it is, and that’s the way the genetic cookie crumbles.” I detect a note of pride in his voice.

Of course, I recognize that tone. I’ve heard it in my own voice from time to time. When the site existed, I used to love poking around Jewhoo, a catalogue of prominent Jews in Western life. Then, in the middle of a Google search one day, I stumbled across jewwatch.com and discovered that under one if its many rubrics—Jewish Controlled Entertainment—was a nearly identical list.

Freud and Marx, Einstein and Bohr, Mendelssohn and Mahler. The brothers Gershwin. The brothers Marx. Woody Allen. Bob Dylan. Franz Kafka. Claude Lévi-Strauss. Bobby Fischer. Jews may take tremendous pride in their aristocracy, but we fetishize it at our own peril; to suggest that we’re chosen, rather than that we make our own choices, curdles quickly into a useful argument for anti-Semites who’d love to claim that the objects of their derision are immutable vermin. It can’t be an accident that the most aggressive debunkers of Jewish essentialism, including the participants in this story, are generally Jews themselves. The arguments come in handy when the ugly stuff is trotted out, too.

Personally, I’m always struck by how many Jews confess to a certain ambivalence about the volume and visibility of their accomplishments, as if there were something slightly vulgar or shameful about them. The friend who introduced me to Jewhoo confided that a friend of his, also Jewish, kept a list of Jews he wished were not. I realized I kept the same mental list. (Andy Fastow, the crook from Enron, is currently No. 1.)

A few years ago, I myself lunged for the easy joke when a non-Jewish friend asked what I did the summer I attended—for one miserable season only, I’d like to stress—Jewish summer camp. Oh, I told him. More or less what you’d expect. Banking lessons rather than canoeing, moot court rather than color wars. Recently, I also found myself quoting—with relish—Sarah Silverman’s reaction to being taken to task by a watchdog group for using the word chink in her stand-up: “As a Jew, I’m really, really nervous we’re losing control of the media.”Perhaps one of the most subtle, insidious things about Cochran and Harpending’s study is how it plays off a bias privately held by many Jews themselves—that the Ashkenazim are in fact intellectual superiors, and the Sephardim, originally from the Iberian Peninsula, are the handlers, the shylocks, the merchants of 47th Street.

Q: How do you tell the difference between an Ashkenazi and a Sephardi?

A: Show him a chessboard. This, even though Maimonides, arguably the most influential Jewish thinker to ever live, was a Sephardi, and the Sephardim have a perfectly dazzling intellectual history of their own. From the eighth to the eleventh centuries, Spanish Jews served in the courts, served as doctors to the caliphs, and translated all manner of texts, converting Greek and Hebrew into Arabic, and Arabic into Romance languages.

Yet in America, that sense of otherness, which for so long has served as a kind of incentive to strive and achieve, may be dissipating. “I’m no demographer, but I think what’s happened in the U.S. is the normalization of the Jew,” says Leon Botstein, who, as the president of Bard College, has seen all sorts of students cross his field of vision. “They’ve become as complacent and culturally undistinguished as the average, suburban, white middle-class American.”

And maybe that’s the price we pay for our current freedoms. Not, as Seinfeld or Larry David might say, that there’s anything wrong with that.