Guns, Germs, and Steel

by Jared Diamond

  The other mode of formation of complex societies, besides merger under threat of external force, is merger by conquest. A well-documented example is the origin of the Zulu state, in southeastern Africa. When first observed by white settlers, the Zulus were divided into dozens of little chiefdoms. During the late 1700s, as population pressure rose, fighting between the chiefdoms became increasingly intense. Among all those chiefdoms, the ubiquitous problem of devising centralized power structures was solved most successfully by a chief called Dingiswayo, who gained ascendancy of the Mtetwa chiefdom by killing a rival around 1807. Dingiswayo developed a superior centralized military organization by drafting young men from all villages and grouping them into regiments by age rather than by their village. He also developed superior centralized political organization by abstaining from slaughter as he conquered other chiefdoms, leaving the conquered chief’s family intact, and limiting himself to replacing the conquered chief himself with a relative willing to cooperate with Dingiswayo. He developed superior centralized conflict resolution by expanding the adjudication of quarrels. In that way Dingiswayo was able to conquer and begin the integration of 30 other Zulu chiefdoms. His successors strengthened the resulting embryonic Zulu state by expanding its judicial system, policing, and ceremonies.

  This Zulu example of a state formed by conquest can be multiplied almost indefinitely. Native states whose formation from chiefdoms happened to be witnessed by Europeans in the 18th and 19th centuries include the Polynesian Hawaiian state, the Polynesian Tahitian state, the Merina state of Madagascar, Lesotho and Swazi and other southern African states besides that of the Zulus, the Ashanti state of West Africa, and the Ankole and Buganda states of Uganda. The Aztec and Inca Empires were formed by 15th-century conquests, before Europeans arrived, but we know much about their formation from Indian oral histories transcribed by early Spanish settlers. The formation of the Roman state and the expansion of the Macedonian Empire under Alexander were described in detail by contemporary classical authors.

  All these examples illustrate that wars, or threats of war, have played a key role in most, if not all, amalgamations of societies. But wars, even between mere bands, have been a constant fact of human history. Why is it, then, that they evidently began causing amalgamations of societies only within the past 13,000 years? We had already concluded that the formation of complex societies is somehow linked to population pressure, so we should now seek a link between population pressure and the outcome of war. Why should wars tend to cause amalgamations of societies when populations are dense but not when they are sparse? The answer is that the fate of defeated peoples depends on population density, with three possible outcomes:

  Where population densities are very low, as is usual in regions occupied by hunter-gatherer bands, survivors of a defeated group need only move farther away from their enemies. That tends to be the result of wars between nomadic bands in New Guinea and the Amazon.

  Where population densities are moderate, as in regions occupied by food-producing tribes, no large vacant areas remain to which survivors of a defeated band can flee. But tribal societies without intensive food production have no employment for slaves and do not produce large enough food surpluses to be able to yield much tribute. Hence the victors have no use for survivors of a defeated tribe, unless to take the women in marriage. The defeated men are killed, and their territory may be occupied by the victors.

  Where population densities are high, as in regions occupied by states or chiefdoms, the defeated still have nowhere to flee, but the victors now have two options for exploiting them while leaving them alive. Because chiefdoms and state societies have economic specialization, the defeated can be used as slaves, as commonly happened in biblical times. Alternatively, because many such societies have intensive food production systems capable of yielding large surpluses, the victors can leave the defeated in place but deprive them of political autonomy, make them pay regular tribute in food or goods, and amalgamate their society into the victorious state or chiefdom. This has been the usual outcome of battles associated with the founding of states or empires throughout recorded history. For example, the Spanish conquistadores wished to exact tribute from Mexico’s defeated native populations, so they were very interested in the Aztec Empire’s tribute lists. It turned out that the tribute received by the Aztecs each year from subject peoples had included 7,000 tons of corn, 4,000 tons of beans, 4,000 tons of grain amaranth, 2,000,000 cotton cloaks, and huge quantities of cacao beans, war costumes, shields, feather headdresses, and amber.

  Thus, food production, and competition and diffusion between societies, led as ultimate causes, via chains of causation that differed in detail but that all involved large dense populations and sedentary living, to the proximate agents of conquest: germs, writing, technology, and centralized political organization. Because those ultimate causes developed differently on different continents, so did those agents of conquest. Hence those agents tended to arise in association with each other, but the association was not strict: for example, an empire arose without writing among the Incas, and writing with few epidemic diseases among the Aztecs. Dingiswayo’s Zulus illustrate that each of those agents contributed somewhat independently to history’s pattern. Among the dozens of Zulu chiefdoms, the Mtetwa chiefdom enjoyed no advantage whatsoever of technology, writing, or germs over the other chiefdoms, which it nevertheless succeeded in defeating. Its advantage lay solely in the spheres of government and ideology. The resulting Zulu state was thereby enabled to conquer a fraction of a continent for nearly a century.

  PART FOUR

  AROUND THE WORLD IN FIVE CHAPTERS

  CHAPTER 15

  YALI’S PEOPLE

  WHEN MY WIFE, MARIE, AND I WERE VACATIONING IN Australia one summer, we decided to visit a site with well-preserved Aboriginal rock paintings in the desert near the town of Menindee. While I knew of the Australian desert’s reputation for dryness and summer heat, I had already spent long periods working under hot, dry conditions in the Californian desert and New Guinea savanna, so I considered myself experienced enough to deal with the minor challenges we would face as tourists in Australia. Carrying plenty of drinking water, Marie and I set off at noon on a hike of a few miles to the paintings.

  The trail from the ranger station led uphill, under a cloudless sky, through open terrain offering no shade whatsoever. The hot, dry air that we were breathing reminded me of how it had felt to breathe while sitting in a Finnish sauna. By the time we reached the cliff site with the paintings, we had finished our water. We had also lost our interest in art, so we pushed on uphill, breathing slowly and regularly. Presently I noticed a bird that was unmistakably a species of babbler, but it seemed enormous compared with any known babbler species. At that point, I realized that I was experiencing heat hallucinations for the first time in my life. Marie and I decided that we had better head straight back.

  Both of us stopped talking. As we walked, we concentrated on listening to our breathing, calculating the distance to the next landmark, and estimating the remaining time. My mouth and tongue were now dry, and Marie’s face was red. When we at last reached the air-conditioned ranger station, we sagged into chairs next to the water cooler, drank down the cooler’s last half-gallon of water, and asked the ranger for another bottle. Sitting there exhausted, both physically and emotionally, I reflected that the Aborigines who had made those paintings had somehow spent their entire lives in that desert without air-conditioned retreats, managing to find food as well as water.

  To white Australians, Menindee is famous as the base camp for two whites who had suffered worse from the desert’s dry heat over a century earlier: the Irish policeman Robert Burke and the English astronomer William Wills, ill-fated leaders of the first European expedition to cross Australia from south to north. Setting out with six camels packing food enough for three months, Burke and Wills ran out of provisions while in the desert north of Menindee. Three successive times, they encountered and were rescued by
well-fed Aborigines whose home was that desert, and who plied the explorers with fish, fern cakes, and roasted fat rats. But then Burke foolishly shot his pistol at one of the Aborigines, whereupon the whole group fled. Despite their big advantage over the Aborigines in possessing guns with which to hunt, Burke and Wills starved, collapsed, and died within a month after the Aborigines’ departure.

  My wife’s and my experience at Menindee, and the fate of Burke and Wills, made vivid for me the difficulties of building a human society in Australia. Australia stands out from all the other continents: the differences between Eurasia, Africa, North America, and South America fade into insignificance compared with the differences between Australia and any of those other landmasses. Australia is by far the driest, smallest, flattest, most infertile, climatically most unpredictable, and biologically most impoverished continent. It was the last continent to be occupied by Europeans. Until then, it had supported the most distinctive human societies, and the least numerous human population, of any continent.

  Australia thus provides a crucial test of theories about intercontinental differences in societies. It had the most distinctive environment, and also the most distinctive societies. Did the former cause the latter? If so, how? Australia is the logical continent with which to begin our around-the-world tour, applying the lessons of Parts 2 and 3 to understanding the differing histories of all the continents.

  MOST LAYPEOPLE WOULD describe as the most salient feature of Native Australian societies their seeming “backwardness.” Australia is the sole continent where, in modern times, all native peoples still lived without any of the hallmarks of so-called civilization—without farming, herding, metal, bows and arrows, substantial buildings, settled villages, writing, chiefdoms, or states. Instead, Australian Aborigines were nomadic or seminomadic hunter-gatherers, organized into bands, living in temporary shelters or huts, and still dependent on stone tools. During the last 13,000 years less cultural change has accumulated in Australia than in any other continent. The prevalent European view of Native Australians was already typified by the words of an early French explorer, who wrote, “They are the most miserable people of the world, and the human beings who approach closest to brute beasts.”

  Yet, as of 40,000 years ago, Native Australian societies enjoyed a big head start over societies of Europe and the other continents. Native Australians developed some of the earliest known stone tools with ground edges, the earliest hafted stone tools (that is, stone ax heads mounted on handles), and by far the earliest watercraft, in the world. Some of the oldest known painting on rock surfaces comes from Australia. Anatomically modern humans may have settled Australia before they settled western Europe. Why, despite that head start, did Europeans end up conquering Australia, rather than vice versa?

  Within that question lies another. During the Pleistocene Ice Ages, when much ocean water was sequestered in continental ice sheets and sea level dropped far below its present stand, the shallow Arafura Sea now separating Australia from New Guinea was low, dry land. With the melting of ice sheets between around 12,000 and 8,000 years ago, sea level rose, that low land became flooded, and the former continent of Greater Australia became sundered into the two hemi-continents of Australia and New Guinea (Figure 15.1 on Chapter 15).

  The human societies of those two formerly joined landmasses were in modern times very different from each other. In contrast to everything that I just said about Native Australians, most New Guineans, such as Yali’s people, were farmers and swineherds. They lived in settled villages and were organized politically into tribes rather than bands. All New Guineans had bows and arrows, and many used pottery. New Guineans tended to have much more substantial dwellings, more seaworthy boats, and more numerous and more varied utensils than did Australians. As a consequence of being food producers instead of hunter-gatherers, New Guineans lived at much higher average population densities than Australians: New Guinea has only one-tenth of Australia’s area but supported a native population several times that of Australia’s.

  Why did the human societies of the larger landmass derived from Pleistocene Greater Australia remain so “backward” in their development, while the societies of the smaller landmass “advanced” much more rapidly? Why didn’t all those New Guinea innovations spread to Australia, which is separated from New Guinea by only 90 miles of sea at Torres Strait? From the perspective of cultural anthropology, the geographic distance between Australia and New Guinea is even less than 90 miles, because Torres Strait is sprinkled with islands inhabited by farmers using bows and arrows and culturally resembling New Guineans. The largest Torres Strait island lies only 10 miles from Australia. Islanders carried on a lively trade with Native Australians as well as with New Guineans. How could two such different cultural universes maintain themselves across a calm strait only 10 miles wide and routinely traversed by canoes?

  Compared with Native Australians, New Guineans rate as culturally “advanced.” But most other modern people consider even New Guineans “backward.” Until Europeans began to colonize New Guinea in the late 19th century, all New Guineans were nonliterate, dependent on stone tools, and politically not yet organized into states or (with few exceptions) chiefdoms. Granted that New Guineans had “progressed” beyond Native Australians, why had they not yet “progressed” as far as many Eurasians, Africans, and Native Americans? Thus, Yali’s people and their Australian cousins pose a puzzle inside a puzzle.

  When asked to account for the cultural “backwardness” of Aboriginal Australian society, many white Australians have a simple answer: supposed deficiencies of the Aborigines themselves. In facial structure and skin color, Aborigines certainly look different from Europeans, leading some late-19th century authors to consider them a missing link between apes and humans. How else can one account for the fact that white English colonists created a literate, food-producing, industrial democracy, within a few decades of colonizing a continent whose inhabitants after more than 40,000 years were still nonliterate hunter-gatherers? It is especially striking that Australia has some of the world’s richest iron and aluminum deposits, as well as rich reserves of copper, tin, lead, and zinc. Why, then, were Native Australians still ignorant of metal tools and living in the Stone Age?

  It seems like a perfectly controlled experiment in the evolution of human societies. The continent was the same; only the people were different. Ergo, the explanation for the differences between Native Australian and European-Australian societies must lie in the different people composing them. The logic behind this racist conclusion appears compelling. We shall see, however, that it contains a simple error.

  AS THE FIRST step in examining this logic, let us examine the origins of the peoples themselves. Australia and New Guinea were both occupied by at least 40,000 years ago, at a time when they were both still joined as Greater Australia. A glance at a map (Figure 15.1) suggests that the colonists must have originated ultimately from the nearest continent, Southeast Asia, by island hopping through the Indonesian Archipelago. This conclusion is supported by genetic relationships between modern Australians, New Guineans, and Asians, and by the survival today of a few populations of somewhat similar physical appearance in the Philippines, Malay Peninsula, and Andaman Islands off Myanmar.

  Once the colonists had reached the shores of Greater Australia, they spread quickly over the whole continent to occupy even its farthest reaches and most inhospitable habitats. By 40,000 years ago, fossils and stone tools attest to their presence in Australia’s southwestern corner; by 35,000 years ago, in Australia’s southeastern corner and Tasmania, the corner of Australia most remote from the colonists’ likely beachhead in western Australia or New Guinea (the parts nearest Indonesia and Asia); and by 30,000 years ago, in the cold New Guinea highlands. All of those areas could have been reached overland from a western beachhead. However, the colonization of both the Bismarck and the Solomon Archipelagoes northeast of New Guinea, by 35,000 years ago, required further overwater crossings of dozens of miles. T
he occupation could have been even more rapid than that apparent spread of dates from 40,000 to 30,000 years ago, since the various dates hardly differ within the experimental error of the radiocarbon method.

  At the Pleistocene times when Australia and New Guinea were initially occupied, the Asian continent extended eastward to incorporate the modern islands of Borneo, Java, and Bali, nearly 1,000 miles nearer to Australia and New Guinea than Southeast Asia’s present margin. However, at least eight channels up to 50 miles wide still remained to be crossed in getting from Borneo or Bali to Pleistocene Greater Australia. Forty thousand years ago, those crossings may have been achieved by bamboo rafts, low-tech but seaworthy watercraft still in use in coastal South China today. The crossings must nevertheless have been difficult, because after that initial landfall by 40,000 years ago the archaeological record provides no compelling evidence of further human arrivals in Greater Australia from Asia for tens of thousands of years. Not until within the last few thousand years do we encounter the next firm evidence, in the form of the appearance of Asian-derived pigs in New Guinea and Asian-derived dogs in Australia.

  Thus, the human societies of Australia and New Guinea developed in substantial isolation from the Asian societies that founded them. That isolation is reflected in languages spoken today. After all those millennia of isolation, neither modern Aboriginal Australian languages nor the major group of modern New Guinea languages (the so-called Papuan languages) exhibit any clear relationships with any modern Asian languages.