What do you think?
Rate this book
335 pages, Hardcover
First published March 27, 2018
We geneticists may be the barbarians coming late to the study of the human past, but it is always a bad idea to ignore barbarians. We have access to a type of data that no one has had before, and we are wielding these data to address previously unapproachable questions about who ancient peoples were.. This book has many very, very good qualities. It is, without doubt, the best modern summary of ancient genome research and how it is transforming our understanding of the past available. However, it also carries some very deep, and dangerous, flaws. Reich is so keen to move us forward with new techniques that he tramples past cultural, sociological and anthropological scholarship that helps us to understand how we create narratives and guard against bias. In doing so, his book reinforces destructive ideas about race; human cognition and psychology and class and power. Perhaps ironically, in seeking to free us from antiquated scholarship, Reich plays straight back into dominant narratives that have explained - and justified - racial inequality for centuries.
Most people accept that the biological differences between males and females are profound, and that they contribute to average differences in size and physical strength as well as in temperament and behavior, even if there are questions about the extent to which particular differences are also influenced by social expectations and upbringing (for example, many of the jobs in industry and the professions that women fill in great numbers today had few women in them a century ago). Today we aspire both to recognize that biological differences exist and to accord everyone the same freedoms and opportunities regardless of them. It is clear from the abiding average inequities that persist between women and men that fulfilling these aspirations is a challenge, and yet it is important to accommodate and even embrace the real differences that exist, while at the same time struggling to get to a better place.This view, that gender inequality is just a bit of thorny issue society is working through, that most people accept that gendered differences in 'temperament' are 'profound' bears little resemblance to any serious scholarship on either gender, or neuroscience (which consistently finds less and less gendered differences), or for that matter the goddamn zeitgeist at the moment, and summarises Reich's dismissiveness.
Scientists interested in studying genetic variation in Native American populations feel frustrated with this situation. I understand something of the devastation that the coming of Europeans and Africans to the Americas wrought on Native American populations, and its effects are also evident everywhere in the data I and my colleagues analyze. But I am not aware of any cases in which research in molecular biology including genetics—a field that has arisen almost entirely since the end of the Second World War—has caused major harm to historically persecuted groups.and leads on to hints of wanting to disregard agreements with tribal councils not to proselytise around this research:
I wonder if the distrust that has emerged among some Native Americans might be, in the balance, doing Native Americans substantial harm. I wonder whether as a geneticist I have a responsibility to do more than just respect the wishes of those who do not wish to participate in genetic research, but instead should make a respectful but strong case for the value of such research.
We scientists are conditioned by the system of research funding to justify what we do in terms of practical application to health or technology. But shouldn’t intrinsic curiosity be valued for itself? Shouldn’t fundamental inquiry into who we are be the pinnacle of what we as a species hope to achieve? Isn’t an attribute of an enlightened society that it values intellectual activity that may not have immediate economic or other practical impact? The study of the human past—as of art, music, literature, or cosmology—is vital because it makes us aware of aspects of our common condition that are profoundly important and that we heretofore never imagined.
I have deep sympathy for the concern that genetic discoveries about differences among populations may be misused to justify racism. But it is precisely because of this sympathy that I am worried that people who deny the possibility of substantial biological differences among populations across a range of traits are digging themselves into an indefensible position, one that will not survive the onslaught of science. In the last couple of decades, most population geneticists have sought to avoid contradicting the orthodoxy. When asked about the possibility of biological differences among human populations, we have tended to obfuscate, making mathematical statements in the spirit of Richard Lewontin about the average difference between individuals from within any one population being around six times greater than the average difference between populations. We point out that the mutations that underlie some traits that differ dramatically across populations—the classic example is skin color—are unusual, and that when we look across the genome it is clear that the typical differences in frequencies of mutations across populations are far less. But this carefully worded formulation is deliberately masking the possibility of substantial average differences in biological traits across populations.
They did not want to be part of a study that suggested a major West Eurasian incursion into India without being absolutely certain as to how the whole-genome data could be reconciled with their mitochondrial DNA findings. They also implied that the suggestion of a migration from West Eurasia would be politically explosive. They did not explicitly say this, but it had obvious overtones of the idea that migration from outside India had a transformative effect on the subcontinent.
We wrote that the people of India today are the outcome of mixtures between two highly differentiated populations, “Ancestral North Indians” (ANI) and “Ancestral South Indians” (ASI), who before their mixture were as different from each other as Europeans and East Asians are today. The ANI are related to Europeans, central Asians, Near Easterners, and people of the Caucasus, but we made no claim about the location of their homeland or any migrations. The ASI descend from a population not related to any present-day populations outside India. We showed that the ANI and ASI had mixed dramatically in India. The result is that everyone in mainland India today is a mix, albeit in different proportions, of ancestry related to West Eurasians, and ancestry more closely related to diverse East Asian and South Asian populations. No group in India can claim genetic purity.
This review will likely be updated as I mull over or re-read the book.
[…] when we discover biological differences governing behavior, they may not be working in the way we naively assume. — David Reich, Who We Are and How We Got Here.
Reich has done a tremendous job condensing the work of many people and disparate areas of research into a compelling story that is potentially more informative for the history and process behind the scientific discoveries than the conclusions or his commentary on their societal effects. While the book is highly recommended based alone on the wealth of new ideas and potential to upturn old facts accepted by many, and is the reason I gave it a high rating rather than because I agree with everything said, it should be read with caution and an eye for "what is not said" for reasons pointed out below.
The book is mainly divided into an introductory portion, where the story of the Neanderthals helps provide a basis to go over techniques used in the ancient DNA field. Reich then moves across the globe—from Europe through India, the Americas, East Asians, and Africa—and goes over different migratory patterns that have been revealed by ancient DNA analysis. In addition, as is the case with India, he shows cases where endogamy (marrying within certain groups) can be demonstrated by analysis of highly unlikely similarity of DNA coding regions across time in specific populations. Further, he also shows how cases like the "Star Cluster" can help demonstrate cases in which specific males (or groups of males) had an outsized levels of breeding success, potentially due to war or migration as mentioned previously. An interesting question that he does not really address is the use of ancient DNA analysis to show how monogamy or polygamy play out in actuality, or if there was more cheating going on than would be expected giving stated societal norms across time and regions. Lastly, he ends looking both at the future (good) and the ethical implications of ancient DNA analysis (the weakest part of the book, more on that later). Overall, the style suites the topic really well and is a great way to get people new to the field acquainted with a forest-level view.
Reich does a convincing job of showing the advantages of ancient DNA analysis over traditional archeology in certain areas, such as pointing out the discrepancy between archeologists claiming that for there to have been a large incursion of non-Indians into that subcontinent, replacing people and leaving a genetic footprint, that there would be carbon, etc. evidence of burnt towns, etc. But the well recorded fall of Rome by the Visigoths and others did not leave such a record to the degree anticipated, throwing such conclusions into doubt. This can be captured in the classic phrase "absence of evidence is not the evidence of absence".
However, and this is a theme about my criticisms of the book, he does not provide examples or speculate on places where the archeological record does show migration or invasion but there is not much ancient or modern DNA evidence left. Two scenarios (of many) would be an invasion where the invading population did not breed much with the locals despite large changes to civilization (think modern American wars) or pass through migrations on the way to some other destination (if those occurred). It would have been informative for him to spend time on the limits of what could possibly be known given ancient DNA basically relies on the dynamics of sex to have occurred in some predicted pattern (e.g. conquering males impregnating conquered females). Further, it is not clear how much the Star Cluster or similar traits is due to a single male or many closely related males, e.g. whether there is a limitation in what this type of analysis can tell us. These might be hidden within academic reviews, but the point of this book should be to give a high-level view of the pros and cons of ancient DNA analysis without a reader needing to get their hands dirty on the first pass.
On the other hand, he does a good job pointing out several neat ideas, such as due to the random splitting of DNA during production of gametes, that several generations back one is unlikely to contain DNA from all ones ancestors (by sexual reproduction). In addition, he does a good job at attacking old dogmas that are based on bad assumptions, such as Richard Lewontin's 1972 study The Apportionment of Human Diversity (see Lewontin's Fallacy, that don't take into account the whole genome or correlations between variations across the genome. This type of thinking is still prevalent, as can be seen in a recent National Geographic issue, see There’s No Scientific Basis for Race—It's a Made-Up Label.
In addition, his small aside about finding that the cochlear contains the best store of ancient DNA is fun and could potentially have been an opportunity to point out serendipity in science (should that be the case here). There are several other times, such as the story of discovering "ghost" populations that may no longer exists but related Europeans and Native Americans that was resolved finding the Mal'ta boy, where he brings up cool stories of how science leads to hypotheses turns to field work and final novel insights about the world. This is captured in a nice assertion Reich makes near the beginning:
We scientists are conditioned by the system of research funding to justify what we do in terms of practical application to health or technology. But shouldn’t intrinsic curiosity be valued for itself? Shouldn’t fundamental inquiry into who we are be the pinnacle of what we as a species hope to achieve? Isn’t an attribute of an enlightened society that it values intellectual activity that may not have immediate economic or other practical impact? The study of the human past—as of art, music, literature, or cosmology—is vital because it makes us aware of aspects of our common condition that are profoundly important and that we heretofore never imagined. — David Reich, Who We Are and How We Got Here.
And it reminds me of Richard Feynman's excellent The Value of Science essay and a key quote:
Another value of science is the fun called intellectual enjoyment which some people get from reading and learning and thinking about it, and which others get from working in it. This is an important point, one which is not considered enough by those who tell us it is our social responsibility to reflect on the impact of science on society. — Richard Feynman The Value of Science.
Reich also gives overviews of several techniques used in the field to identify likely common ancestors (Four Population Test) and to group current and past groups of people (e.g. principal component analysis). These are supplemented by excellent diagrams. However, he doesn't spend much time pointing out to the reader problems with these techniques or how they get around them. This is especially important as it relates to discussions of grouping people into categories based on (in the book) obvious delineations between say Europeans and some Asians subcategories.
Our initial approach was to carry out a principal component analysis, which can identify combinations of mutation frequencies that are most efficient at finding differences among samples. — David Reich, Who We Are and How We Got Here.
As a scientist, and knowing how quickly new fields can evolve and old methods be found to contain technical and conceptual errors, I am alarmed by Reich's lack of giving any kind of confidence (mathematical or otherwise) about statements being made that upturn old archeological or other theories. Given many studies he cited are less than a decade, sometimes only a couple years old, this is concerning. He does not spend much time going over more caveats to the technical methods (e.g. extraction of DNA from ancient samples, though he does talk about some initial challenges and solutions in the case of Neanderthal DNA) or conceptual ideas (e.g. Four Population Test). This is evidenced, for example, in his out of place bringing up of the Jefferson-Hemings relationship that adds nothing to the story but he presents as if it has been conclusively shown (with genetics, while glossing over the caveats). More humility about the possibilities of ancient DNA analysis would have strengthened the book.
Reich would also have done well to specifically state who he is referring to when he makes comments about those wanting to return to a 'racially pure' state, while he leaves their timescale for determining purity indefinite. Those discussing maintaining a recent European stock in their writings (e.g. The Daily Stormer, American Renaissance, Occidental Dissent, etc.) are slightly different that those proposing old Nordic Theories and similar stories (e.g. see The Long Journey, The Rising Tide of Color: Against White World Supremacy, etc.). He does briefly mention the Eurogenes and several other blogs, but only in passing and not directly in relation to his reference to 'racists' and 'bigots'. Further, he then contradicts himself by pointing out:
However, in Europe, where we have made most progress in the ancient DNA revolution so far, we know that by four thousand years ago, many populations were already highly similar in their ancestry composition to those of today. […] For example, the classic measure of genetic differentiation between two British populations is about one hundred times smaller than the same measurement of population differentiation comparing Europeans to East Asians. — David Reich, Who We Are and How We Got Here.
That he does not attempt to reconcile these comments about populations that are relatively homogenous and have not mixed much over recent history leaves room for people to misinterpret or use such findings to justify their beliefs.
Ancient DNA has established major migration and mixture between highly divergent populations as a key force shaping human prehistory, and ideologies that seek a return to a mythical purity are flying in the face of hard science. — David Reich, Who We Are and How We Got Here.
In addition, at the end of several chapters and throughout the book Reich makes reference to 'racial purity' not being a thing—without taking care to note that purity depends on the timescale used and, thus, is an annoying strawman. As noted above, he also contradicts this statement in several cases, among which include the distinct ethnic groups in Indian that have been maintained for tens of generations even among physically mixed populations.
Around a third of Indian groups experienced population bottlenecks as strong or stronger than the ones that occurred among Finns or Ashkenazi Jews. […]Many of the population bottlenecks in India were also exceedingly old. […] It meant that after the population bottleneck, the ancestors of the Vysya had maintained strict endogamy, allowing essentially no genetic mixing into their group for thousands of years. Even an average rate of influx into the Vysya of as little as 1 percent per generation would have erased the genetic signal of a population bottleneck. The ancestors of the Vysya did not live in geographic isolation.[…] And the Vysya were not unique. A third of the groups we analyzed gave similar signals, implying thousands of groups in India like this. — David Reich, Who We Are and How We Got Here.
In addition, he also seems focused on the idea of human migrations to the exclusion of focusing on how ancient DNA can tell us about changes occurring in non-migratory populations (thought he hints at the end of the book about this). For example, this could address Clark's A Farewell to Alms assertion about rich Britons breeding more being a reason for the industrial revolution and would be a starting point for many interesting analyses. During the discussion of the low occurrence of mixture between physically inter-mixed groups within India, e.g. endogamy or the caste system, he then goes on a tangent about his Jewishness and how he sympathized with the (unnamed) people who were prevent from finding love outside their ethnic/social group. These very overt tendencies to favor mixture over non-mixture are concerning in that he doesn't state in reality what guides his (and those in the fields) scientific questions and how that might bias future hypotheses or research, impacting interpretation of the past and having consequences for how society at large interprets the fields results.
The genome revolution provides us with a shared history that, if we pay proper attention, should give us an alternative to the evils of racism and nationalism, and make us realize that we are all entitled equally to our human heritage. [emphasis mine] — David Reich, Who We Are and How We Got Here.
This book, along with the excellent The Neuroscience of Intelligence by Richard Haier and many others will start to raise questions that need to be addressed by scientists and non-scientists. To put it bluntly, old and new research points toward the ability to quantify intelligence (broadly defined or by IQ) and DNA (and other) analysis has shown fairly definitively that there are different clusters of humans (e.g. ethnicities and ancestral groups for those wanting to avoid the loaded 'race' category). The question remains that once people combine the two areas of research, as China is attempting to do specifically looking at the genetics of g, are we as a society equipped to handle the results regardless of what they might be (especially if differences appear)? Will nationalism of the kind focused on celebrating a shared culture be instead directed toward war-like nationalism focused on extermination of those with traits that are not desired (by some group)? His blanket negative statements on anything tribal related—be that racism, nationalism, endogamy, etc.—cloud useful insights and suggestions that could be gleaned by a more nuanced position.
In an individualistic society, ethnic history reminds us of the enduring consequences of centuries-old cultural patterns into which each individual is born. […] It is not personal merit but simply good fortune to be born into a group whose values and skills make life easier to cope with.[…]Substantial reshuffling of the rankings of nations and races at different stages of history undermine genetic explanations in general. A reshuffling of the IQ rankings of American ethnic groups within a period of half a century26 undermines the theory of genetic determination of intelligence, even aside from questions about the tests themselves. The fact that black orphans raised by white families have IQs at or above the national average27 is even stronger evidence against that theory. — Thomas Sowell, Ethnic America.
Thomas Sowell in Ethnic America appears to attribute many of the differences between ethnic groups to differences in culture and notes that persistent disparities between African-Americans/Hispanics and Caucasian-descent/Asians need to be explained. In his famous How Much Can We Boost IQ and Scholastic Achievement? and subsequent essays and books, Arthur Jensen proposes that IQ is heritable. The Bell Curve, Levin's thought-provoking Why Race Matters, and many others point toward potential genetic differences between groups. Reich somewhat addresses this field of research but does so haphazardly and at times commits the same errors as he accuses other of, e.g. when criticizing Watson and others, he notes that there is no genetic evidence of different IQ of (sub-Saharan) Africans, ignoring the evidence that there is a lower IQ (but that we don't yet know the genetic origin). He offers the following solution to deal with the fallout of finding differences between human groups:
The right way to deal with the inevitable discovery of substantial differences across populations is to realize that their existence should not affect the way we conduct ourselves. As a society we should commit to according everyone equal rights despite the differences that exist among individuals. If we aspire to treat all individuals with respect regardless of the extraordinary differences that exist among individuals within a population, it should not be so much more of an effort to accommodate the smaller but still significant average differences across populations. — David Reich, Who We Are and How We Got Here.
Given human nature toward tribalism and noticing differences, this is a naïve solution. It would have been nice for him to at least briefly note how this type of thinking jives with how humans behave in the real, non-utopian world. Seeing as he makes mention of the misuse of archeology in the past by National Socialists and others, this is not too much to ask. There are many other gaps along these lines that he should have addressed, but instead danced around or ignored.