What are the most important findings from your book?
Abraham’s Children is a sequel of sorts to a previous book, Taboo: Why Black Athletes Dominate Sports and Why We’re Afraid to Talk About It. Both examined the emerging field of population genetics, which is the scientific and more nuanced term for what is popularly called “race.” As I discussed in both books, the folkloric notion of race is scientifically unreliable as it is based on some pre-scientific notions, such as skin color. Population, however, refers more specifically to ancestry. Although the term is also inexact, it is used by scientists to mean a group of people that has remained insular over hundreds or thousands of years because of geographical isolation (such as West African blacks for much of their evolutionary history, or Icelanders more recently) or even because of religious or cultural restrictions (such as Jews, Parsis and the Amish). Population groups share many genotypic characteristics–scientists are now able to identify gene frequencies common to insular groups known as haplotypes–that often result in phenotypic differences in functionality or appearance, which can include anything from disease proclivities to height, body proportion, or even brain functions, including IQ.
Taboo focused on why different genetic population groups tend to do well in certain athletic endeavors and not in others. Does evolution proscribe body types and physiology in identifiable populations? The short answer is “yes”. While there is a great deal of overlap on average (the fat center of the distribution curve), clear differences show up on the tails, at the elite level. For example, speaking in very broad terms, whites, particularly of Eurasian ancestry, dominate elite strength related sports, such as weight lifting, hammer throw, javelin, shot put, etc.
Because of certain physical and physiological characteristics common to all people of African ancestry, including lower natural body fat and longer limbs relative to their torsos, blacks dominate at the elite level of running. But East African and West Africans have different genotypes and phenotypes. Using the universal sport of running as a measuring stick, elite runners of West African ancestry dominate in sprinting; for example they hold 494 of the top 500 100 metre times. Yet there are no elite distance runners of West African ancestry. East Africans are mediocre sprinters–no East African (or White or Asian for that matter) has ever broken 10 seconds in the 100 metres. Yet East Africans, particularly those who trace their ancestry to the mountainous Rift Valley, an evolutionary forge for distance runners, dominate endurance races.
Abraham’s Children applied a genetic prism to the biblical concept of “chosenness” to re-open the age-old question of “Who is a Jew?”
Taboo, published in 2000, as the first crude maps of the human genome was just being sketched, left unexamined the question of groups of people, such as Jews, who are not today referred to as a “race” but share many of the defining characteristics of a population. Throughout most of their three thousand year history, until the Holocaust, Jews were considered a race by others and Jews often considered themselves a race–a people defined by their historical commitment to intermarriage, as outlined in the Torah. Yet the term is simplistic; over thousands of years, there have been innumerable examples of Jews marrying outside their faith and accepting converts into their religion. That did not stop the Nazis from killing millions of Jews because of their religious belief that they are a “people.” Understandably, after World War II, the term pseudo-scientific term “race” became discredited. Today Jews do not think of themselves in purely racial terms and are rarely thought of that way today. Yet there is still a belief that Jews are more than just a group united by a common belief system. Jews call themselves a “people.” What does that mean?
Abraham’s Children applied a genetic prism to the biblical concept of “chosenness” to re-open the age-old question of “Who is a Jew?” Are Jews defined by faith, ancestry, culture or a combination of the above? The most direct, and perhaps most explosive finding, is that Jews are in fact a fuzzy-edged yet definable population. From a purely genetic perspective, the Jewish history of inbreeding has left an indelible mark when it comes to disease proclivities. According to a Michael Hammer, an eminently respected population geneticist at the University of Arizona, the rate of introgression of non-Jewish genes into the gene pool of Ashkenazi Jews (Jews of Central and Eastern European descent) since the formation of Ashkenazi Jewry about one thousand years ago stood at less than 0.5 percent per generation until intermarriage became rampant over the last two generations. That’s among the lowest rates of dilution of any genetic population in the world. Consequently because of those many centuries of cultural, and therefore genetic, insularity, and inbreeding, Jews, especially European-descended Jews, suffer from more than 40 diseases at higher frequencies than other populations.
The question remains: if population inbreeding can impact disease patterns, could it also influence other characteristics? Clearly the most explosive revelation in the book is that there are prominent scientists who believe that the reasons behind the high incidence of certain “Jewish diseases”–ones that impact the neurological pathways (e.g. Tay Sachs, Gaucher) and DNA repair activities (e.g. breast and ovarian cancer)–may also help explain why Jews are so disproportionately prominent and successful, especially in jobs that require high IQ. Jews have been recognized as high achievers since early in the 19th century. As Mark Twain wrote: “[T]he Jews constitute but one percent of the human race. It suggests a nebulous dim puff of stardust lost in the blaze of the Milky Way. Properly the Jew ought hardly to be heard of, but he is heard of, has always been heard of. He is as prominent on the planet as any other people, and his commercial importance is extravagantly out of proportion to the smallness of his bulk. His contributions to the world’s list of great names in literature, science, art, music, finance, medicine, and abstruse learning are also away out of proportion to the weakness of his numbers. He has made a marvelous fight in the world, in all the ages; and has done it with his hands tied behind him.” Abraham’s Children offers a compelling discussion of the cultural and genetic factors that might explain this.