In this masterpiece, Jared Diamond sets himself the task of answering the most obvious, the most important and yet the most difficult question about human history - why did it unfold so differently for different populatons on the continents and islands of the earth?

It is the finest book I have ever read, brimming with insight and knowledge, and delivered with style. This page is a tribute and introduction to the themes of the book, which Diamond has also expounded in various articles and lectures.


History followed different courses for different peoples because of differences among peoples' environments, not because of biological differences among peoples themselves.

1. The Question
2. The Method - A Natural Experiment of History
3. The Arrow of Disease
4. Isolation & Communication
5. Around The World in Five Chapters
6. The Future of Human History as a Science


I've set myself the modest task of trying to explain the broad pattern of human history, on all the continents, for the last 13,000 years. Why did history take such different evolutionary courses for peoples of different continents?

My theme, then, is the different courses of history for peoples of different continents.
As we all know, Eurasians, especially peoples of Europe and eastern Asia, have spread around the globe, to dominate the modern world in wealth and power. Other peoples, including most Africans, survived, and have thrown off European domination but remain far behind in wealth and power. Still other peoples, including the original inhabitants of Australia, the Americas, and southern Africa, are no longer even masters of their own lands but have been decimated, subjugated, or exterminated by European colonialists. Why did history turn out that way, instead of the opposite way?
Why weren't Native Americans, Africans, and Aboriginal Australians the ones who conquered or exterminated Europeans and Asians?

This question can easily be pushed back one step further. By the year A.D. 1500, the
approximate year when Europe's overseas expansion was just beginning, peoples of the different continents already differed greatly in technology and political organization. Much of Eurasia and North Africa was occupied then by Iron Age states and empires, some of them on the verge of industrialization. Two Native American peoples, the Incas and Aztecs, ruled over empires with stone tools and were just starting to experiment with bronze. Parts of sub-Saharan Africa were divided among small indigenous Iron Age states or chiefdoms. But all peoples of Australia, New Guinea, and the Pacific islands, and many peoples of the Americas and sub-Saharan Africa, were still living as farmers or even still as hunter/gatherers with stone tools.
Obviously, those differences as of A.D. 1500 were the immediate cause of the modern
world's inequalities. Empires with iron tools conquered or exterminated tribes with stone tools. But how did the world evolve to be the way that it was in the year A.D. 1500?

This question, too can be easily pushed back a further step, with the help of written
histories and archaeological discoveries. Until the end of the last Ice Age around 11,000 B.C., all humans on all continents were still living as Stone Age hunter/gatherers. Different rates of development on different continents, from 11,000 B.C. to A.D. 1500, were what produced the inequalities of A.D. 1500. While Aboriginal Australians and many Native American peoples remained Stone Age hunter/gatherers, most Eurasian peoples, and many peoples of the Americas and sub-Saharan Africa, gradually developed agriculture, herding, metallurgy, and complex political organization. Parts of Eurasia, and one small area of the Americas, developed indigenous writing as well. But each of these new developments appeared earlier in Eurasia than elsewhere.
So, we can finally rephrase our question about the evolution of the modern world's
inequalities as follows. Why did human development proceed at such different rates on
different continents for the last 13,000 years? Those differing rates constitute the broadest pattern of history, the biggest unsolved problem of history, and my subject today.

To appreciate how far from obvious is the answer to this question, imagine that an alien historian from Outer Space had visited the Earth 50,000 years ago. If that visitor had been asked to predict which continent's people would develop technology most rapidly, and who would conquer whom, what do you think that the alien would have predicted? The alien might well have answered "Africa," because human history in Africa had a six-million-year head start over history on the other continents. Or, the alien might instead have predicted "Australia," the continent with perhaps the earliest evidence of anatomically and behaviorally fully modern humans, and the continent with by far the earliest evidence for human use of watercraft. The visitor would surely have written off Europe, where Homo sapiens still hadn't even arrived as of 50,000 years ago. To that visitor, the state of the world as we see it today would be incomprehensible. What were the reasons for the unexpected outcome?

        - Introduction from a UCLA Lecture which summarises the book

Read Chapter One of the book: "Up To The Starting Line" [external]


Moriori and Maori history constitutes a brief , small-scale natural experiment that tests how environments affect human societies. ...Of course, such purposeful experiments cannot be carried out on human societies. Instead, scientists must look for 'natural experiments', in which something similar befell humans in the past. (p54)

Such an experiment unfolded during the settlement of Polynesia. Scattered over the Pacific Ocean beyond New Guinea are thousands of islands differing greatly in area, isolation, elevation, climate, productivity and biological resources.
For most of human history those islands lay far beyond the reach of watercraft. Around 1200 BC a group of farming, fishing, seafaring people from the Bismarck Archipelago north of New Guinea finally succeeded in reaching some of those islands. Over the following centuries their descendants colonized virtually every habitable scrap of land in the Pacific.
The process was mostly complete by 500 AD, with the last few islands settled around 1000 AD.

Thus, within a modest time span, enormously diverse island environments were settled by colonists all of whom stemmed from the same founding populations. The ultimate ancestors of all modern Polynesian populations shared essentially the same culture, language, technology, and set of domesticated plants and animals. Hence Polynesian history constitutes a natural experiment allowing us to study human adaptation. (p55)

What can we learn from all of Polynesia about environmental influences on human societies?
Polynesian societies ran the gamut from fairly egalitarian village societies to some of the most stratified societies in the world, with many hierarchially ranked lineages and with chief and commoner classes whose members married within their own class. In political organization, Polynesian islands ranged from landscapes divided into independent tribal or village units, up to multi-island proto-empires that devoted standing military establishments to invasions of other islands and wars of conquest. (p57)

How can all that variation be explained? Contributing to these differences among Polynesian societies were at least six sets of environmental variables among Polynesian islands: island climate, geological type, marine resources, area, terrain fragmentation and isolation. (p58)

Polynesian island societies differed greatly in their economic specialization, social complexity, political organization, and material products, related to differences in population size and density, related in turn to differences in island area, fragmentation, and isolation and in opportunities for subsistence and intensifying food production. All those differences among Polynesian societies developed, within a relatively short time and modest fraction of the Earth's surface, as environmentally related variations on a single ancestral society... In short Polynesia furnishes us with a convincing example of environmentally related diversification of human societies in operation. (p65)


The grimmest example of the role of germs in history is much on our minds this month, as we recall the European conquest of the Americas that began with Columbus’s voyage of 1492. Numerous as the Indian victims of the murderous Spanish conquistadores were, they were dwarfed in number by the victims of murderous Spanish microbes. These formidable conquerors killed an estimated 95 percent of the New World’s pre-Columbian Indian population.

Why was the exchange of nasty germs between the Americas and Europe so unequal? Why didn’t the reverse happen instead, with Indian diseases decimating the Spanish invaders, spreading back across the Atlantic, and causing a 95 percent decline in Europe’s human population? Similar questions arise regarding the decimation of many other native peoples by European germs, and regarding the decimation of would-be European conquistadores in the tropics of Africa and Asia.

The infectious diseases that visit us as epidemics share several characteristics. First, they spread quickly and efficiently from an infected person to nearby healthy people, with the result that the whole population gets exposed within a short time. Second, they’re "acute" illnesses: within a short time, you either die or recover completely. Third, the fortunate ones of us who do recover develop antibodies that leave us immune against a recurrence of the disease for a long time, possibly our entire lives. Finally, these diseases tend to be restricted to humans; the bugs causing them tend not to live in the soil or in other animals. All four of these characteristics apply to what Americans think of as the once more-familiar acute epidemic diseases of childhood, including measles, rubella, mumps, pertussis, and smallpox.

It is easy to understand why the combination of those four characteristics tends to make a disease run in epidemics. The rapid spread of microbes and the rapid course of symptoms mean that everybody in a local human population is soon infected, and thereafter either dead or else recovered and immune. No one is left alive who could still be infected. But since the microbe can’t survive except in the bodies of living people, the disease dies out until a new crop of babies reaches the susceptible age - and until an infectious person arrives from the outside to start a new epidemic.

A classic illustration of the process is given by the history of measles on the isolated Faeroe Islands in the North Atlantic. A severe epidemic of the disease reached the Faeroes in 1781, then died out, leaving the islands measles-free until an infected carpenter arrived on a ship from Denmark in 1846. Within three months almost the whole Faeroes population - 7,782 people - had gotten measles and then either died or recovered, leaving the measles virus to disappear once again until the next epidemic. Studies show that measles is likely to die out in any human population numbering less than half a million people. Only in larger populations can measles shift from one local area to another, thereby persisting until enough babies have been born in the originally infected area to permit the disease’s return.

To sustain themselves, acute infections need a human population that is sufficiently numerous and densely packed that a new crop of susceptible children is available for infection by the time the disease would otherwise be waning. Hence measles and other such diseases are also known as "crowd diseases."
Crowd diseases could not sustain themselves in small bands of hunter-gatherers and slash-and-burn farmers. the evolution of our crowd diseases could only have occurred with the buildup of large, dense human populations, first made possible by the rise of agriculture about 10,000 years ago, then by the rise of cities several thousand years ago. Indeed, the first attested dates for many familiar infectious diseases are surprisingly recent: around 1600 B.C. for smallpox (as deduced from pockmarks on an Egyptian mummy), 400 b.c. for mumps, 1840 for polio, and 1959 for AIDS.
When the human population became sufficiently large and concentrated, we reached the stage in our history when we could at last sustain crowd diseases confined to our species.
But that presents a paradox: such diseases could never have existed before. Instead they had to evolve as new diseases. Where did those new diseases come from?

Evidence emerges from studies of the disease-causing microbes themselves. In many cases molecular biologists have identified the microbe’s closest relative. Those relatives also prove to be agents of infectious crowd diseases--but ones confined to various species of domestic animals and pets! Among animals too, epidemic diseases require dense populations, and they’re mainly confined to social animals that provide the necessary large populations. Hence when we domesticated social animals such as cows and pigs, they were already afflicted by epidemic diseases just waiting to be transferred to us.

How, then, does all this explain the outcome of 1492--that Europeans conquered and depopulated the New World, instead of Native Americans conquering and depopulating Europe?
Part of the answer, of course, goes back to the invaders’ technological advantages. European guns and steel swords were more effective weapons than Native American stone axes and wooden clubs. Only Europeans had ships capable of crossing the ocean and horses that could provide a decisive advantage in battle. But that’s not the whole answer. Far more Native Americans died in bed than on the battlefield - the victims of germs, not of guns and swords. Those germs undermined Indian resistance by killing most Indians and their leaders and by demoralizing the survivors.

The role of disease in the Spanish conquests of the Aztec and Inca empires is especially well documented. In 1519 Cortés landed on the coast of Mexico with 600 Spaniards to conquer the fiercely militaristic Aztec Empire, which at the time had a population of many millions. That Cortés reached the Aztec capital of Tenochtitlán, escaped with the loss of "only" two-thirds of his force, and managed to fight his way back to the coast demonstrates both Spanish military advantages and the initial naïveté of the Aztecs. But when Cortés’s next onslaught came, in 1521, the Aztecs were no longer naive; they fought street by street with the utmost tenacity. What gave the Spaniards a decisive advantage this time was smallpox, which reached Mexico in 1520 with the arrival of one infected slave from Spanish Cuba. The resulting epidemic proceeded to kill nearly half the Aztecs. The survivors were demoralized by the
mysterious illness that killed Indians and spared Spaniards, as if advertising the Spaniards’ invincibility. By 1618 Mexico’s initial population of 20 million had plummeted to about 1.6 million.
In the century or two following Columbus’s arrival in the New World, the Indian population is estimated to have declined by about 95 percent. The main killers were European germs, to which the Indians had never been exposed and against which they therefore had neither immunologic nor genetic resistance. Smallpox, measles, influenza, and typhus competed for top rank among the killers. As if those were not enough, pertussis, plague, tuberculosis, diphtheria, mumps, malaria, and yellow fever came close behind.

The one-sided exchange of lethal germs between the Old and New worlds is among the most striking and consequence-laden facts of recent history. Whereas over a dozen major infectious diseases of Old World origins became established in the New World, not a single major killer reached Europe from the Americas. The sole possible exception is syphilis, whose area of origin still remains controversial.
That one-sidedness is more striking with the knowledge that large, dense human populations are a prerequisite for the evolution of crowd diseases. If recent reappraisals of the pre-Columbian New World population are correct, that population was not far below the contemporaneous population of Eurasia. Some New World cities, like Tenochtitlán, were among the world’s most populous cities at the time. Yet Tenochtitlán didn’t have awful germs waiting in store for the Spaniards. Why not?

The main reason becomes clear, however, if we ask a simple question: From what microbes could any crowd diseases of the Americas have evolved? We’ve seen that Eurasian crowd diseases evolved from diseases of domesticated herd animals. Significantly, there were many such animals in Eurasia. But there were only five animals that became domesticated in the Americas: the turkey in Mexico and parts of North America, the guinea pig and llama/alpaca (probably derived from the same original wild species) in the Andes, the Muscovy duck in tropical South America, and the dog throughout the Americas.
That extreme paucity of New World domestic animals reflects the paucity of wild starting material. About 80 percent of the big wild mammals of the Americas became extinct at the end of the last ice age, around 11,000 years ago, at approximately the same time that the first well- attested wave of Indian hunters spread over the Americas. Among the species that disappeared were ones that would have yielded useful domesticates, such as American horses and camels. Debate still rages as to whether those extinctions were due to climate changes or to the impact of Indian hunters on prey that had never seen humans. Whatever the reason, the extinctions removed most of the basis for Native American animal
domestication - and for crowd diseases.

So on this 500th anniversary of Columbus’s discovery, let’s try to regain our sense of perspective about his hotly debated achievements. There’s no doubt that Columbus was a great visionary, seaman, and leader. There’s also no doubt that he and his successors often behaved as bestial murderers. But those facts alone don’t fully explain why it took so few European immigrants to initially conquer and ultimately supplant so much of the native population of the Americas. Without the germs Europeans brought with them - germs that were derived from their animals - such conquests might have been impossible.

        - Excerpt from article for Discover magazine


For the last 10,000 years the Tasmanians represented a study of isolation unprecedented in human history except in science fiction novels. Here were 4,000 Aboriginal Australians cut off on an island, and they remained totally cut off from any other people in the world until the year 1642, when Europeans "discovered" Tasmania. What happened during those 10,000 years to that isolated 4,000 person society? And what about nearby Flinders Island, which originally supported a population of 200 cut-off Aboriginal Australians?

When Europeans discovered Tasmania in the 17th century, it had technologically the simplest, most "primitive" human society of any society in the modern world. Native Tasmanians could not light a fire from scratch, they did not have bone tools, they did not have multi-piece stone tools, they did not have axes with handles, they did not have spear-throwers, they did not have boomerangs, and they did not even know how to fish. What accounts for this extreme simplicity of Tasmania society? Part of the explanation is that during the 10,000 years of isolation, the Aboriginal Australians, who numbered about 250,000, were inventing things that the isolated 4,000 Tasmanians were not inventing, such as boomerangs. Incredibly, though, archeological investigations have shown one other thing: during those
10,000 years of isolation, the Tasmanians actually lost some technologies that they had carried from the Australian mainland to Tasmania. Notably, the Tasmanians arrived in Tasmania with bone tools, and bone tools disappear from archeological record about 3,000 years ago. That's incredible, because with bone tools you can have needles, and with needles you can have warm clothing. Tasmania is at the latitude of Vladivostok and Chicago: it's snowy in the winter, and yet the Tasmanians went about either naked or just with a cape thrown over the shoulder.

How do we account for these cultural losses and non-inventions of Tasmanian society? Flinders Island was even more extreme - that tiny society of 200 people on Flinders Island went extinct several millenia ago. Evidently, there is something about a small, totally isolated human society that causes either very slow innovation or else actual loss of existing inventions. That result applies not just to Tasmania and Flinders, but to other very isolated human societies. There are other examples. The Torres Strait islanders between Australia and New Guinea abandoned canoes. Most Polynesian societies lost bows and arrows, and lost pottery. The Polar Eskimos lost the kayak, Dorset Eskimos lost dogs and bow drills, and Japan lost guns.

When firearms arrived in Europe, there were European princes who similarly banned firearms, and there were European princes who banned printing, but you can guess what happened. When a prince in the middle of Europe banned firearms, within a short time the prince next door who did not ban firearms either walked in and conquered, or else the prince who banned firearms quickly realized his or her mistake and reacquired firearms from next door. The banning of the guns could work only in isolated Japan, where there were no neighbors as a threat, and where there were no neighbors from whom to reacquire the technology.

So these stories of isolated societies illustrate two general principles about relations between human group size and innovation or creativity. First, in any society except a totally isolated society, most innovations come in from the outside, rather than being conceived within that society. And secondly, any society undergoes local fads. By fads I mean a custom that does not make economic sense. Societies either adopt practices that are not profitable or for whatever reasons abandon practices that are profitable. But usually those fads are reversed, as a result of the societies next door without the fads out-competing the society with the fad, or else as a result of the society with the fad, like those European princes who gave up the guns, realizing they're making a big mistake and reacquiring the fad. In short, competition between human societies that are in contact with each other is what drives the invention of new technology and the continued availability of technology.

The other lesson that I would like to draw from history concerns what is called the optimal fragmentation principle. Namely, if you've got a human group, is that group best organized as a single large unit, or is it best organized as a number of small units, or is it best fragmented into a lot of small units?
...I propose to get some empirical information about this question by comparing the histories of China and Europe. Why is it that China in the Renaissance fell behind Europe in technology?

...China was also on the verge of building powerful  water-powered machinery before the Industrial  Revolution in Britain, but the emperor said "Stop," and so  that was the end of the water-powered machinery in  China. In contrast, in Europe there were princes who said no to electric lighting, or to printing, or to guns. And,  yes, in certain principalities for a while printing was  suppressed. But because Europe in the Renaissance was  divided among 2,000 principalities, it was never the case that there was one idiot in command of all Europe who could abolish a whole technology. Inventors had lots of chances, there was always competition between different states, and when one state tried something out that proved valuable, the other states saw the opportunity and adopted it. So the real question is, why was China chronically unified, and why was Europe chronically disunified? Why is Europe disunified to this day?

The answer is geography. Just picture a map of China and a map of Europe. China has a smooth coastline. Europe has an indented coastline, and each big indentation is a peninsula that became an independent country, independent ethnic group, and independent experiment in building a society: notably, the Greek peninsula, Italy, the Iberian peninsula, Denmark, and Norway/Sweden. Europe had two big islands that became important independent societies, Britain and Ireland, while China had no island big enough to become an independent society until the modern emergence of Taiwan. Europe is transected by mountain ranges that split up Europe into different principalities: the Alps, the Pyrenees, Carpathians - China does not have mountain ranges that transect China. In Europe big rivers flow radially - the Rhine, the Rhone, the Danube, and the Elbe - and they don't unify Europe. In China the two big rivers flow parallel to each other, are separated by low-lying land, and were quickly connected by canals.
For those geographic reasons, China was unified in 221 B.C. and has stayed unified most of the time since then, whereas for geographic reasons Europe was never unified. Augustus couldn't do it, Charlemagne couldn't do it, and Napoleon and Hitler couldn't unify Europe. To this day, the European Union is having difficulties bringing any unity to Europe.

        - Excepts from lecture "A Natural History Of Wealth"


How Africa Became Black.

An Empire of Uniformity : How China Became Chinese.

Just who are the Japanese?

Paradises Lost : Easter Island & Pitcairn Island.

10,000 years of Solitude : Tasmania




History is classified as a social science, which is considered not quite scientific. But let’s remember the etymology of the world science. It’s not derived from a Latin word that meant ‘replicated laboratory experiments carried out by little men wearing white lab coats’, instead the etymology of our word science is the Latin word sciential which means knowledge.

In science we seek knowledge by whatever methodologies are available and appropriate. There are many fields that nobody hesitates to consider science even though replicated laboratory experiments in those fields would be immoral or illegal or impossible. For example astronomers cannot turn Aldebaron or Betelgeuse on, increase the luminocity of Sirius and maintain other stars as unmanipulated controls. Geologists can’t start a glacier here and stop an ice age over there, and palaeontologists cannot experiment with designing a new set of dinosaurs and then exterminating them again. Nevertheless astronomers, and geologists and palaeontologists have still gained considerable insight into their historical fields by other means. And so we should surely be able to understand human history, because introspection and preserved writings give us far more insight into the ways of past humans than we shall ever have into the ways of past dinosaurs.

For that reason I’m optimistic that we can eventually arrive at convincing explanations for these broadest patterns of human history.


Human history, as something separate from the history of animals, began in Africa about 7 million years ago. Around that time, a population of African apes broke up into several populations, of which one proceeded to evolve into modern gorillas, a second into the two modern chimps, and the third into humans. The gorilla line apparently spilt off slightly before the split between the chimp and the human lines. (p36)

The near-simultaneous disappearance of so many large species raises an obvious question: what caused it? An obvious possible answer is that they were killed off or else eliminated indirectly by the first arriving humans... The critics respond with a counter-theory: perhaps the giants succumbed instead to a change in climate, such as a severe drought on the already chronically dry Australian continent. Personally, I can't fathom why Australia's giants should have survived innumerable droughts in their tens of millions of years of Australian history, and then have chosen to drop dead simultaneously (at least on a time scale of millions of years) precisely and coincidentally when the first humans arrived. The giants became extinct not only in dry central Australia but also in drenching wet New Guinea and southeastern Australia. They became extinct in every habitat without exception, from deserts to cold rain forest and tropical rain forest. Hence it seems to me most likely that the giants were indeed exterminated by humans, both directly (by being killed for food) and indirectly (as the result of fires and habitat modification caused by humans). But regardless of whethe rthe overkill hypothesis or climate hypothesis proves correct, the disappearance of all of the big animals in Australia / New Guinea had heavy consequences for subsequent human history.
(pp 42-44)

Much of human history has consisted of unequal conflicts between the haves and the have-nots: between peoples with farmer power and those without it, or between those who acquired it at different times.

The peoples of areas with a head start on food production thereby gained a head start on the path leading to guns, germs and steel.  The result was a long series of collisions between the haves and have-nots of history.

Those few peoples who remained hunter-gathers into the 20th century escaped replacement by food producers because they were confined to areas not fit for food production, especially deserts and Arctic regions.

In a traditional New Guinea society, if a New Guinean happened to encounter an unfamiliar New Guinean while both were away from their respective villages, the two engaged in a long discussion of their relatives, in an attempt to establish some relationship and hence some reason why the two should not attempt to kill each other. (p272)

The official religions and patriotic fervor of many states make their troops willing to fight suicidally. The latter willingness is one so strongly programmed into us citizens of modern states, by our schools and churches and governments, that we forget what a radical break it makes with previous human history.
Naturally, what makes patriotic and religious fanatics such dangerous opponents is not the deaths of the fanatics themselves, but their willingness to accept the deaths of a fraction of their number in order to annihilate or crush their infidel enemy. Fanaticism in war, of the type that drove recorded Christian and Islamic conquests, was probably unknown on Earth until chiefdoms and especially states emerged within the last 6,000 years. (pp 281-282)

It is not the case that societies on the different continents were comparable to
each other until 3000 BC, whereupon western Eurasian societies suddenly developed writing and began for the first time to pull ahead in other respects as well. Instead, already by 3000 BC, there were Eurasian and North African societies not only with incipient writing but also with centralised state governments, cities, widespread use of tools and weapons, use of domesticated animals for transport and traction and mechanical power, and reliance on agriculture and domesticated animals for food.
Throughout most or all parts of other continents, none of these things existed at that time; some but not all of them emerged later in parts of the Native Americas and sub-Subharan Africa, but only over the course of the next five millennia; and none of them emerged in Aboriginal Australia. That should already warn us that the roots of western Eurasian dominance in 1500 AD lie in the preliterate past before 3000 BC.


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