Guns, Germs, and Steel: The Fates of Human Societies

Reviewed by
Garrett Hardin
University of Calfornia
Ecology, Evolution and Marine Biology
Santa Barbara, CA

Originally appeared in POPULATION AND DEVELOPMENT REVIEW, 23: 4.

Jared Diamond’s latest book continues a distinguished tradition of quasi-universal histories written from a particular point of view. In 1920 H. G. Wells assembled An Outline of History, as seen by one immersed in the wonders of science and technology. In 1969, Kenneth Clark emphasized the role of the visual arts in shaping Civilisation. The work here discussed was written by a man well trained in biology and ecology. The problems posed are uncomfortably relevant to our time.

Guns, Germs, and Steel—the title is a reference to the factors that supposedly explain the Spanish conquest of the Americas—seeks to explain the deeper causes of unequal development, notably European ascendancy over the rest of the world, in modern history. Diamond sees these causes as primarily environmental (even just accidents of geography), mediated by agriculture, population size, social organization, and technology. He paints with a broad and confident brush, with the perhaps immodest ambition of telling historians how to write history.

I express my admiration of this work. The book is wide ranging and the examples wisely chosen; I would be quite willing to impose this discriminating synopsis on my grandchildren. The ecological survey of the fates of previous societies should help prepare them for the challenges now crowding in on ours. Let those few words stand for a much larger body of praise that could legitimately be heaped on this book.

Nevertheless, and at the risk of generating an unbalanced review, I will focus on only one (albeit a crucial) facet of the work, an aspect that I think deserves criticism at length because it raises issues that are poorly dealt with by many other books in our time. As one who is put in the same pigeon-holes as the author— biology and ecology—I submit that in his treatment of one topic Diamond unwisely follows what the British call "vulgar" opinion, ignoring certain implications of fundamental biological knowledge. Since many other authors follow the same aberrant path, it is no more than just that it should be treated here at length. I refer to the topic of racism.

Asking whether today’s observable differences in the competencies of Aboriginal Australians and Europeans are due to real differences between the peoples themselves, Diamond takes a firm stand (p. 19):

The objection to such racist explanations is not just that they are loathsome, but also that they are wrong. Sound evidence for the existence of human differences in intelligence that parallel human differences in technology is lacking. In fact…modern "Stone Age" peoples are on the average probably more intelligent, not less intelligent, than industrialized peoples.

Comments on the unconventional racism of Diamond’s final assertion (which should perhaps be labeled "reverse racism") are postponed to the close of this review. For the present, several more obvious criticisms should be recorded.

First, before he embarks on the factual substance of his argument, Diamond sows the ground with a passionately prejudicial term, namely "loathsome." This approach is, unfortunately, popular among both racists and anti-racists.

Second, like so many moderns who indignantly reject ethnocentrism, he embraces what we can only call ethnofugalism, an obsessive flight from the center of one’s inherited culture. Paradoxically, such ethnofugalism has become the ethnocentrism of a minority now called the elite." (Early in the present century Edwin Arlington Robinson wittily satirized this attitude in his poem, Miniver Cheevy.")

Third, the demand for "sound evidence" of differences between races raises the profound problem of the "burden of proof." Statistical proofs often evoke doubts because, long before there was an academic subject called statistics, logicians cautioned against the fallacy of post hoc, ergo propter hoc—"after this, therefore because of this." (Example: "Summer days are longer than winter days; this proves that daylight, like so many other things, expands when heated.") What biologists call ‘field data"—data gathered from the uncontrolled happenings in daily life—seldom settles a controversial question because there are usually far more variables than there are observationally derived equations. Statistical studies are most fruitful when a laboratory approach is feasible, for then the number of observations (equations) can be made to exceed what seems to be a reasonable number of variables to assume.

Diamond’s considered position on the reality and importance of racial differences is well stated on page 25:

Authors are regularly asked by journalists to summarize a long book in one sentence. For this book, here is such a sentence: ‘History followed different courses for different peoples because of differences among peoples’ environments, not because of biological differences among peoples themselves."

For the entire 425 pages of his text Diamond maintains this position, which, as will be illustrated below, can only be labeled biophobic—truly a surprising position for a biologist to take. Since about 1930, the biophilic position concerning breeding-group differences has led to a quite opposite conclusion. The theoretical reasons for this seem overwhelming to modem biologists, many of whom take precisely the reverse position from that assumed by Diamond: they put the burden of proof firmly on those who assert the unimportance of genetic differences between breeding-groups. Genetic differences are to be assumed unless and until the contrary position is rigorously established. Faced with that position on the burden of proof, biophobes have a tough job ahead of them. (Of course the observed differences between well-isolated groups may or may not be "significant." Significance is a much harder question to deal with.)

Strange as it may seem, the most fruitful approach to controversial questions is often through pure theory. While not much concerned with biology, the physicist Einstein (according to Banesh Hoffman, p. 18 of Albert Einstein, Creator and Rebel) opened the following royal road to the discovery of deep truths: "When judging a scientific theory, his own or another’s, he asked himself whether he would have made the universe in that way had he been God." Whether Einstein was an atheist or a theist is not the issue: his rhetorical formula forced him to stay on the true path to rationalism. We can take the biological branch of this road in seeking a convincing answer to the puzzle of races.

Two facts from experience dictate the choices of the first two elements of biological theory: (1) the overwhelming stability of genetic material and (2) the equally astonishing occasional instability of genetic material. Were it not for the first fact no species, race, or breeding group would be stable enough for natural selection to exert its usual effect of ‘investing in success," because success would be continually eroded to zero.

And were it not for the second effect—rare, but unstoppable, mutations—there would be no chance for natural selection to meet new environmental challenges by investing in new forms of success. The working out of these two factors produces what we are pleased to call ‘evolution." No biological Einstein has come forward with any believable counter-proposal. (The fulminations of the religiously oriented anti-Darwinians who call themselves ‘scientific creationists" are not worthy of rational analysis. No Einstein has appeared in this almost entirely American fraternity.)

The genetic code that produces the individual human being consists of about 100,000 places (‘loci") on the chromosomes; for each locus on a chromosome the mutation process is capable of producing something like a dozen different determiners (‘alleles"), only one of which is normally present at a specific locus on a particular chromosome. (This is only a rough way of stating the facts, but it is adequate to suggest the tremendous variety of different individuals potentially present in a species. Most of the time, of course, natural selection does not permit the majority of the mutant forms to survive. Geneticists thus generalize: "most mutations are bad.")

We can give no more than the "order of magnitude" of the total potential variety of genetic types in a vertebrate species. The number 100,000 times 1012 does not overestimate the number of possibilities. So even a very tiny percentage of potential survivors yields a number that is tremendous, by ordinary human standards. For this reason the statement of the Declaration of Independence that "All men are created equal" is utterly insupportable. The burden of proof should always be placed on the speaker who says that he has found two persons (not identical twins) who are equal: the "default position" of nonidentity is firmly held by most biologists.

A defensible focus of the Declaration of Independence would be equity, not equality. Equity should be the concern of human legislation that is aimed to be just, impartial, fair. The Declaration should be reworded: "All men are, by this social contract, assigned equal equity in the management of the state." Of course the difference between two individuals may, or may not, be significant for some purpose. The biological knowledge accumulated in the twentieth century has changed the policy question from one of equality to one of the significance of differences. (That doesn’t make it any easierl) But the assertion of equality makes defensible political deductions impossible.

A race is not one individual, but many differing individuals. Comparison of a single item between groups may reveal a difference in their means (‘averages,’ approximately). In standard intelligence tests the mean IQ for East Asians is likely to be 8 units greater than the IQ for European white" stock. How are we to know when a difference in the means is significant?

Obviously the problem of significance becomes even more difficult once we focus on breeding groups (races) rather than individuals; but the solution of this problem will not be made any easier by basing the analysis on the contrary-to-fact assumption of equality. (One can easily mount a plausible argument for the inequality of any two groups.) Whatever we mean by "IQ intelligence," we are measuring qualities that are selected by what we call "civilization." The Chinese can plausibly claim to have been "civilized" for thousands of years longer than Europeans. If the result surprises us we can set about altering it—by establishing more severe conditions of social selection for the characteristics we choose to define as "civilized." Breeding alone does not produce the difference in means, but we are not surprised when a longer endurance of a particular set of social conditions has more effect than a shorter. We need not be the helpless victims of "nature’s" selection; the human choice we empower in the generation of domestic plants and animals could, theoretically, be turned loose on the human species itself. (But would such a choice be wise? That is the question that underlies eugenics.)

The breeding of domesticated animals in experiment stations has revealed general truths whose direct discovery in human beings is forbidden by our taboos against using human beings as experimental animals. A mountain of evidence indicates that every particular allele of a gene, though it probably has one primary chemical effect in cell development, has many effects on the entire organism— many bad," with perhaps one "good" one. When the latter is very good from a human point of view—say increased milk production by a cow—we breed the animals so as to select for the good. Pretty soon we have a strain of cows that are great milk producers. We succeed in this endeavor by carefully controlling the conditions of life for the high producers.

Now for a further experiment. Turn the breed of high producers loose in meadows that are untended by human beings: what happens? The answer is simple: in the absence of human care, the previously human-induced evolution is soon undone. All the alleles involved in producing high-milkers produce other, often subtle, effects that are deleterious from a bovine point of view. Without the human selection of high-milking characteristics, the inherent cost of the other effects of these genes results in their speedy elimination.

Taking a different example: experimental station workers have given up on breeding cattle that are both high milk producers and economical beef producers: the unavoidable genetic costs of two different constellations of alleles is simply too great to make this possible in historic time. This generalization holds true for a multitude of organisms. In a crude way it was discovered thousands of years ago, long before writing was available for recording discovered facts. To be successful, plant and animal breeders must not be too greedy.

Another aspect of the genetic—environmental interaction needs to be introduced. In the early days of Drosophila (fruitfly) genetics, whenever a new mutant was discovered it usually made its possessor markedly feeble in comparison with the "wild type." A new mutant might eliminate one of the bristles: it would then be found that stocks pure for the mutant were significantly enfeebled (though our limited human imagination could not see why the absence of one bristle, say, should make any difference). But as time went on, and the stock was carefully protected against outcrossing with other genetic types, sooner or later the vigor of the "new" stock increased. In such a case, conclusive genetic tests showed that the action of the mutant genes had now been modified by new mutants at other loci. The effects of these new genes was often extremely subtle (from a human point of view). By creating a new genetic environment (‘bristle-loss"), a new natural criterion of natural selection had been created. The term ‘genetic environment" may seem like an oxymoron, but a close examination of the facts shows that it is not.

Once we realize the complexity of natural selection in affecting human history, we are in a position to understand the considerable differences between, say, African blacks and European races. Surveying the large literature of European explorers in Africa before 1850—before the development of modern medicine—we are struck by how unfavorable an environment equatorial Africa was for white explorers. Sickness and death were always just a step away for the whites. As an environment, this area was not nearly so unfavorable for blacks. Why? Basically because they had, for thousands of years, been selected for genes that protected them somewhat from the medical threats of the tropical environment.

In the present century medical researchers have unraveled parts of the tropical puzzle. The various malarias, for instance, are not nearly as devastating for African natives as they are for alien whites. As is now generally known, the gene for sickle cells—distorted red blood cells—in the heterozygous (impure) condition protects against some of the malarias; but it does so at the cost of causing a serious anemia when it is present in the homozygous (pure) condition. Malaria is such a serious disease that a human population can afford the anemias in some individuals so long as other individuals are protected against malaria. When a population of individuals bearing sickle cells is displaced to a nonmalarious environment, the group suffers seriously from the repeated surfacing of the sickle cell gene, without any concomitant benefit. A sickle cell—bearing population and a "normal" population are not equal in either of the contrasting environments.

The sickle cell gene is only one of several that confer significant immunity to one of the malarias. We have much yet to learn about the other genes, but it is clear that each protective gene has its price. Moreover, a wealth of other pathologies flourish in the tropics—many infections by parasitic worms, for instance— and it is clear that human populations long resident in such an environment possess numerous alleles that protect, more or less, against tropical pathologies. Each protective allele exacts its price in the form of other effects that, on balance, are not good for the individual. When a human population that is well protected against tropical diseases is transposed to a nontropical environment, it is to be expected that the alien population will suffer some disadvantage when competing with the resident population. Why? Because the nature of the competition for the migrants has changed.

A simple thought experiment clarifies this point. Consider the assaults of mountaineers on Mt. Everest during the latter half of the twentieth century. Most of these have been led by men of European stock, which stock would be presumed to be unselected for this sort of activity. But the individual adventurers have been exceptional athletes within their own culture; and (in each expedition) a small number of Europeans have been supported by a large detail of men native to the Himalayas: some of them lived in villages at 13,000 feet, others minded flocks at 16,000 feet.

Suppose, now, that a doctrinaire worshipper of the American Declaration of Independence decided he would prove that the statement "All men are created equal" was literally true by enlisting the mountaineering staff not from the vicinity of Mt. Everest but from the lowlands of the Congo. What chance would such a group have in its drive to the 29,000-foot peak? Surely, zero. A committed anti-racist would no doubt insist that the novel new group needs practice before being given such a task; but, in the light if a wealth of biological findings with other species, such a placing of the burden of proof is not acceptable. Nature challenges humanity with inequalities both in the environment and in personnel. The most that human idealists may hope to achieve is equity—for which a price must be paid.

Finally, a word is in order about Diamond’s statement that "Stone Age peoples are on the average probably more Intelligent, not less intelligent, than industrialized peoples." It would be easy to dismiss this as just another display of the ethnofugalistic impulse; but a defense of this unusual assertion can be mounted. When European man sets about devising an intelligence test, it is only natural that he should seek to create diagnostic puzzles that favor what the European tester regards as significant. However, many an explorer who has lived for awhile cheek-by-jowl with Stone Age men ends up by having a definite feeling that ‘primitive" men are often his superior in perceiving and rapidly reacting to the challenges of their environment. The European realizes that his unusual competitors may be superior in hearing, in seeing, and in perceiving the subtleties of their world. The European realizes that if Stone Age men had to devise an intelligence test, it would be different from the European-American IQ test; and the performance of the competitors might well be significantly altered.

This, I think, would be Diamond’s best defense of his ethnofugalistic position. The mythical Man from Mars—intelligent, objective, and not bound by earthly biases—might take this position. No mere Earthling can claim unearthly objectivity. But (in a way) we feel we can understand it. We recognize that no analysis of the nature of human adaptation is complete until we have allowed for the effects of circularity in selection—the sort of process that occurs in sexual selection, which can produce extreme differences in the appearance of the two sexes. In evolution, how the initial small difference comes about is a mystery, but once it has been validated by fashion (so to speak), it can become so extreme as to endanger the survival of the aberrant sex. The "widow bird" of Africa (family Viduinae) furnishes an example. Males have four extra-long tail feathers (10—13 cm.) that have been demonstrated to attract females, to interfere with flying, and to reduce the survival rate of males in the presence of predators. Whatever the full explanation of ‘secondary sexual characteristics" is, the resulting fashion is generally costly to the affected sex. Among humans, the persistent swelling of the breasts in nonlactating females is thought to be such an adaptation to fashion, since nonlactating females of the higher apes have chests as flat as those of the males.

In 1936, the anthropologist V. Gordon Childe concluded his book Man Makes Himself with the following significant passage:

just because tradition is created by societies of men and transmitted in distinctively human and rational ways, it is not fixed and Immutable: It is constantly changing as society deals with ever new circumstances. Tradition makes the man, by circumscribing his behavior within certain bounds; but it is equally true that man makes the traditions.

As our knowledge of genetics and its potentialities deepens, we broaden Childe’s vision to take account of the new knowledge, threatening though it may be to many traditionalists. A new generalization emerges: A genotype determines the potentialities of a single man; but enduring societies of men can also, by controlling and altering environments, cause natural selection to select for different genotypes, for different forms of "success." These in turn require, for the fullest realization of their potentialities, different environments in which to mature. At this point we are moved to echo Childe’s final sentence (omitted above) by saying: "And so, we can repeat with deeper insight, ‘Man makes himself."'

Thus does the aphorism take on new significance. Man does make himself—by choosing among many environments, whose selective characteristics ‘choose" the human beings who survive best in each environment. Man, the would-be master of the future, has to make many decisions. To begin with, how many environments should be cultivated? In the light of history as it is taking place today in central Europe and central Africa, should we encourage multiculturalism within any nation? Since equality is only the ideal of a mythical One World, how is equity to be achieved within a nation? And how is a naive, fashion-driven population to be sensitized to the realities and dangers of ethnofugalism?

None of these profound questions is even hinted at in Diamond’s book, though it is a valuable benchmark of our present state of ignorance.