Guns, Germs, and Steel: The Fates of Human Societies, Jared Diamond, W. W. Norton, 1997, 480 pp.; $27.50
The gaps in achievement among world cultures are an obvious problem for racial egalitarians. If no group is more talented than any other, why did Eurasians rather than Africans split the atom? Why didn’t indigenous Americans invent arithmetic?
Egalitarians usually dodge such questions, citing American “racism” to explain black and Hispanic failures in the United States despite its irrelevance to the “developing (i.e. undeveloped) world.” To his credit, Jared Diamond has confronted this issue head-on. He hopes to explain the attainments of each race—he reluctantly accepts the concept of race—wholly in terms of geography and ecology rather than differences in innate abilities.
Guns, Germs, and Steel should be taken seriously, first, because it has just won a Pulitzer Prize. This will bring it extra attention, and the cachet of the Pulitzer will convince many people that hereditarian accounts of history have been safely disposed of at last. Second, despite his political correctness (“The oldest Java ‘man’ fossils may actually have belonged to a Java woman”) and predictable digs at whites, Prof. Diamond is intellectually serious. He is a vastly more interesting, less tendentious writer than Stephen Jay Gould, whom he resembles in being an academic popularizer of evolutionary biology (Prof. Diamond teaches medicine at UCLA). In fact, when a few years ago I first came across Prof. Diamond’s work in magazines like Discover and Natural History, my reaction was “These are the pieces Gould is trying to write.” Third, as I will explain, everything valid in this book fits nicely into, indeed enriches, the hereditarian view of history.
Prof. Diamond is an environmentalist in the strictest sense. Unlike hereditarians, who typically attribute group differences to both genetic and environmental factors, he considers environmental factors only—chiefly plants, wildlife, and geography. For him, genes account for none of the variance in technology, literacy, military success or other aspects of different cultures. (Whether he thinks genes contribute to individual differences is unclear.) Prof. Diamond therefore sets himself a daunting task: phenomena as complex as cultural divergence are apt to have complex causes, so the fewer variables a theory of divergence permits, the less plausible it is likely to be. It will be interesting to see whether Prof. Diamond’s focus on geography attracts the dread label “reductionist” so often slapped on hereditarians.
Prof. Diamond limits himself as he does because he assumes virtually without argument that all human groups are of identical average intelligence—except perhaps for New Guineans fresh from the Stone Age, who “in mental ability . . . are probably genetically innately superior to Westerners.” These views are defended with obiter dicta that readers of AR have heard before. For example, “sound evidence for the existence of human differences in intelligence that parallel human differences in technology is lacking. . . . [T]ests of cognitive ability (like IQ tests) tend to measure cultural learning and not pure innate intelligence, whatever that is.” As for New Guineans, not only do they strike him as sparkling conversationalists, their Hobbesian milieu of interpersonal violence, accidents and starvation culls the less intelligent. Westerners, because of their governments, written laws, police forces and medical science, experience gentler selective pressures. On top of that, Western children stupefy themselves with TV. (How a mere half century of TV could affect our genes, Prof. Diamond does not say.)
The trouble with this environmentalist boilerplate about IQ is not just that it is wrong, although of course it is that: evidence abounds that the inhabitants of the earth’s various regions differ markedly in mental ability. Physical anthropologists estimate that cranial capacity in humans, a valid estimator of brain size and thereby intelligence, increases by nearly two cubic centimeters for every degree of latitude away from the equator. This boilerplate is also incoherent. If there is no such thing as innate intelligence, one cannot venture the deliciously scandalous suggestion that headhunters possess more of it than white Americans. Most damaging of all, for Prof. Diamond’s purposes, this suggestion inadvertently recognizes that social environments themselves exert selectional pressure. Prof. Diamond does not notice that, even if the first settled Eurasian societies differed from those of genetically similar Africans and Mesoamericans only because of environmental reasons, the individual traits favored within these societies might over time have pushed their populations onto divergent genetic tracks. This is a very important point to which I will return.
Prof. Diamond has therefore done something no responsible scientist should ever do: set out to explain a fact before making sure it is a fact. Asking why the continents came to differ in technology although “human neurobiology” is everywhere the same is like asking how canaries digest meat, or why Napoleon ended up in exile on St. Helena despite winning the battle of Waterloo.
Still, Prof. Diamond is knowledgeable and smart, and the theory he lays out clearly sheds some light on the human past. In outline, he sees mankind’s developmental trajectory in any region of the Earth as determined by the number and kind of domesticable plants and animals the region contained, and its barriers to travel. In particular, the unique advantages in all three respects of the famed “Fertile Crescent” after the last Ice Age 13,000 years ago was the decisive accident of history.
To take farming first, the area of Southwest Asia around the Tigris-Euphrates valley, was reportedly rich in the right wild varieties of wheat and barley. One trait that especially suits a grass species for domestication is the heaviness of its seed—the part that contains the nutrients—and 32 of the world’s 56 heaviest-seeded grass plants are native to Southwest Asia. Only four of these grasses are found in Sub-Saharan Africa and eleven in all of the Americas. (I am no expert, and have no reason to dispute Prof. Diamond’s paleobotany.)
The shift from hunting-gathering to farming, Prof. Diamond argues (surely correctly), was not the inspiration of a lone genius, but was incremental and largely unplanned. Hunter-gatherers first took note of especially desirable plants, then began to return to the most vigorous stands of those plants, then settled permanently near those stands, then began consciously to tend them, and then consciously to sow future crops.
More efficient than hunting or gathering, farming yielded food surpluses that allowed sharp increases in population density, which in turn supported specialized non-farming classes of scribes, intellectuals, soldiers, and, eventually, government bureaucrats. Farm-supported societies tended toward greater complexity, the production of new ideas and inventions, and military domination of their neighbors.
Prof. Diamond argues specifically that all this happened in the Fertile Crescent long before it happened elsewhere in great part because of the accident mentioned before—the presence of so many domesticable plants. This, rather than any inherent superiority of its inhabitants, led to its becoming the “cradle of civilization.” Other parts of the world never had a chance. Either they had no suitable plants at all, or had so few, and began farming so late, that they were overwhelmed by the descendants of those southwest Asians who had begun to urbanize by 8,500 B.C.
Farming was not the whole story, however. Just as important, according to Prof. Diamond, was the presence of large domesticable animals providing high-quality protein, transportation, and energy for work. Animals are also a source of synergy: oxen plus wheels equal wagons. (Attaching wheels to something that could be pulled never occurred to any New Worlder, Prof. Diamond asserts, only because the toy wheels invented by early Mexicans were separated from the llamas of South America by the Isthmus of Panama.) Once again, Eurasia was lucky enough to have most of the large, wild herbivorous mammals that could be domesticated: sheep, goats, cows, pigs and horses. Africa had the buffalo and the horse-like zebra, but zebras are mean-tempered and hard to lasso, while African buffaloes are too ornery to manage. Prof. Diamond even conjures up “Rhino-mounted Bantu shock troops” overrunning the Roman Empire, which did not happen because—but only because—rhinos are insufficiently docile. Prof. Diamond is thus able to dismiss the subsequent dominance of Africa by Europe as “an accident of biogeography.”
Together, domesticated animals and plants conferred a final advantage on Eurasians useful in world conquest: immunity to many diseases. Domesticated animals produce microbes deadly to man, but which can linger in the large populations made possible by farming long enough for their human carriers to develop immunity. (At the same time disease organisms evolve so as not to kill their human hosts too quickly, a point Prof. Diamond makes at length.) The cowless and sheepless natives of the New World, Africa and Australasia, never having been exposed to the communicable diseases of Europeans, succumbed en masse during the age of European exploration. The most famous case of this, of course, was the decimation of the Incas and Aztecs by germs accompanying the Spanish conquistadors. Again, audacity and cleverness had nothing to do with the conquistadors’ military success.
But didn’t the ocean-spanning ships of the Spanish, and the firearms they deployed against New World spears, bespeak intellectual superiority? Prof. Diamond explains western man’s stubborn edge in technology by means of the contours of the Earth’s continents. Eurasia is long, stretching ten thousand miles through the same latitudes, and free of major natural obstacles. No impassable mountain ranges or deserts blocked the diffusion of farming techniques and new ideas. The relative constancy of climate allowed farm crops and domesticated animals to flourish once they spread, increasing population density all over Eurasia, which led to further innovations that radiated forth in their turn.
The frequency of inventors in all populations is the same, Prof. Diamond assures us, so, all else being equal, the more people there are the more inventions there will be. Inventions build on each other, leading in the end to European guns and ships. The Americas, on the other hand, are tall and thin, with their different regions occupying different latitudes. Domesticable plants native to California would not have grown in Tierra del Fuego even had they gotten there, which in any case they could not because of the Panamanian bottleneck. Sub-Saharan Africa for its part was isolated by the Sahara, so until recent centuries knew nothing of developments in the rest of the world.
Prof. Diamond tries hard to encompass everything, but sometimes the going gets ad hoc. As China is very large and unusually tractable geographically, for instance, why didn’t it conquer the world? Because, says Prof. Diamond, the very ease of crisscrossing China kept competing centers of power and innovation from forming. It was so unified that when the emperor decreed something, such as, in the 15th century, the end of exploration, every Chinese went obligingly along.
Prof. Diamond sweeps other facts that resist geographic pigeonholing under the QWERTY principle. The first typewriters featured the awkward QWERTY keyboard, meant to slow typists down so as not to jam the then-primitive typing mechanism. But so many typists learned QWERTY, and passed it on to future typists, that it remains entrenched even though electronic word processing permits more ergonomic keyboard arrays. Just so, suggests Prof. Diamond, many of the “idiosyncrasies” that may bias some cultures against innovation may be due to accidents that arose for “trivial, temporary local reasons,” and became fixed as “influential, long-lasting cultural features.” Pure chance is thus assigned a place in the fate of cultures, but not the talents of the individuals who make them up.
There are several objections to his theory that Prof. Diamond anticipates. One is the absence of controlled experiments. If Prof. Diamond is right, had Bantus literally switched places with the inhabitants of Europe 10,000 years ago today’s Bantus would occupy the world role Europeans do now. What direct corroborative evidence is there for this? Prof. Diamond cites the failure of Europeans to domesticate African wildlife and the keenness with which Plains Indians adopted horses to show that personnel is irrelevant, but anecdotes are no substitute for systematic comparative studies.
This weakness is not fatal. As Prof. Diamond observes, other hard-to-test theories about remote origins, like evolution and continental drift, get by on indirect evidence because of their great explanatory power: if they are correct, they explain a great deal. But Prof. Diamond’s account is much weaker, and does not actually explain what it claims to, because it does not adequately distinguish the conditions necessary for civilization from those sufficient to produce it. The distinction, one Prof. Diamond fully acknowledges, bears stressing. You can’t start a fire in the absence of oxygen—oxygen is necessary for combustion—but it does not follow that once you have oxygen you automatically have combustion. The presence of oxygen does not explain the Chicago fire.
Likewise, Prof. Diamond is no doubt right that a large industrial society cannot form without plentiful food, compliant animals and contact with outside ideas. The descendants of a band of Europeans stranded on a Pacific atoll 5,000 years ago would not be building moon rockets today; a potential Newton would be too busy gathering coconuts to wonder why they fall. But it does not follow from this near-truism that just any human group with crops, animals and outside contacts will rise as high as European man—that, given these factors, civilization is automatic. It certainly does not follow that any two human groups will exploit these resources to precisely the same extent.
In fact, different groups as they now exist plainly do not respond identically to identical inputs. Japanese played no part in the creation of modern science, but once exposed to it they embraced it, and now lead the world in making cars, computers and other high-tech gadgets. Africans have been aware of European technology for just as long, but microchip firms have not sprung up in Kenya.
Prof. Diamond replies that unlike Kenya, Japan can build on “a long history of literacy, metal machinery, and centralized government,” ultimately traceable to flora, fauna and stimulating ideas imported earlier. However, the “history” of any individual begins at birth, so Prof. Diamond’s theory predicts that Kenyans reared in the west should be just as adept at technology as the average westerner. But we do not find this. Descendants of Africans have lived in the US for ten generations, and have been immersed in its culture (and unconnected with Africa) for at least five. Yet black contributions to technology remain negligible. As is well known, American blacks reared from infancy in middle-class white households show adult levels of IQ and scholastic achievement barely above the American black mean. Similarly, though less dramatically, Koreans reared in European families display IQs characteristic of Koreans, not the slightly lower ones of their adoptive parents. Current members of different groups do not exploit resources, including knowledge, with equal efficiency, and there is no reason to think they did so in the past. Given everything we know, if we returned in a time machine to Africa circa 10,000 BC and transplanted the Bantus to a land of milk, honey, horses and heavy-seed grasses, they would not take to city-building as readily as their Eurasian contemporaries.
All of which suggests that the comparatively easy domestication of foodstuffs and animals in Eurasia at most only accelerated group divergences already under way. This in any case is what evolutionary logic demands. The different environments they had occupied for tens of thousands of years previously would have forced Africans, Europeans, Asians and Amerindians apart by 8,000 B.C. Prof. Diamond devotes only two dismissive sentences to this idea:
Many northern Europeans assume that technology thrives in a rigorous climate where survival is impossible without technology, and withers in a benign climate where clothing is unnecessary and bananas supposedly fall off the trees. An opposite view is that benign environments leave people free from the constant struggle for existence, free to devote themselves to innovation.
What Prof. Diamond should have done at this point was to ask which scenario is more plausible, and, if possible, integrate these ideas into his own hypothesis. Instead he resorts to a debater’s trick: meet an unwelcome idea with its polar opposite, and hope the two cancel each other out.
This blindness to human evolution is the great weakness of Guns. I mentioned earlier the selective pressures applied to Eurasians by the transition to farming. Surprisingly—amazingly—Prof. Diamond traces the genetic effects of domestication on plants and animals (today’s dogs and cats have smaller brains than their feral counterparts), on animal-borne diseases, and on the human immune system, but it never occurs to him that domestication, agriculture and urbanization might also have altered the domesticators in far-reaching ways. That this did in fact happen is a central theme of contemporary sociobiology.
Take the ability to soothe a nervous horse. The neurological basis for this ability must have shown up from time to time as a mutation, but in the absence of horses it conferred no survival value, and did not take hold. But once horses were tamed, the ability to handle them became valuable, hence fitness-conferring, hence fixed in the population. Or take foresight, always somewhat useful, but possibly more useful, hence more apt to be selected for, when grain must be stored, seeds husbanded, and other tasks requiring visualization of the future must be done.
Cooperation and Morality
But the deepest changes in the human psyche induced by urbanization concern co-operation and intelligence. Everyone in a small band of hunter-gatherers is related, so general altruism enhances inclusive genetic fitness. By aiding any other band member, even at some cost to myself, I automatically aid a carrier of some of my own genes. Greater concern for closer relatives aside, no advantage accrues to discrimination about whom to help. But when (thanks to farming) hundreds of people live together, pure helpfulness may subordinate my own genetic interests to those of an unrelated stranger. Being able to tell relatives from non-relatives suddenly becomes adaptive, and the enhanced cognitive abilities needed to do so are likely to develop.
But it is also in my interest to help strangers willing to help me back. So there is also pressure to develop the yet more sophisticated ability to keep track of those I have helped, those in my debt, proven welshers (who won’t get my help again), to calculate the odds that I can get away with accepting help today without having to reciprocate tomorrow, and so on. And the more adept urban dwellers became at these calculations, the subtler their interactions became, which selected for even better abilities to handle these interactions. Many evolutionary psychologists trace much of modern man’s intellectual attainments to the cognitive demands of multiperson interactions (Eurasian man’s, of course, but this they don’t say).
Therefore, even if, improbably, early Eurasian urbanization was an accident, hundreds of generations of city life itself would have molded Eurasians to differ from Africans, Australasians and Amerindians in significant genetic ways: to be more intelligent, more gregarious, and to adopt norms closer to the golden rule. In fact, Richard Lynn, Edward Miller and J. P. Rushton, who have conjectured about the evolutionary effects of climate during hominid evolution, could easily add the genetic changes triggered by urbanization to their models of prehistory.
But how could Prof. Diamond, a self-proclaimed evolutionary biologist, have missed these arguments about the effects of urbanization? They are not the preserve of a tiny coterie. There is now a highly developed mathematical theory of the evolution of cooperation, expounded in several books well known to academics, and articles about it appear regularly in top journals, like Science, Nature, and Journal of Theoretical Biology. Prof. Diamond must know of these developments. Why does he ignore them?
In part, because of Occam’s razor. Since (Prof. Diamond thinks) race differences are not needed to explain history, looking for them is pointless. To a certain extent this conviction is justified: if we didn’t already know from other evidence that the races differ, his case would be quite persuasive. Guns is easily the best environmentalist anthropology ever written. But Prof. Diamond’s scientific edifice stands on the usual moralistic foundation. He makes very plain his opposition to “racism.” Unlike Stephen Jay Gould, Prof. Diamond is too honest to cheat for ideological reasons, but he so dislikes “racists” that he can’t separate his desire to refute them from the happy feeling of actually having done so. I honestly wonder how Prof. Diamond would react if forced to deal with the detailed evidence of race differences that has been accumulating for the past half century.