Jared Diamond Quotes

Perhaps our greatest distinction as a species is our capacity, unique among animals, to make counter-evolutionary choices.

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

Much of human history has consisted of unequal conflicts between the haves and the have-nots.

[T]he values to which people cling most stubbornly under inappropriate conditions are those values that were previously the source of their greatest triumphs.

With the rise of chiefdoms around 7,500 years ago, people had to learn, for the first time in history, how to encounter strangers regularly without attempting to kill them.

In short, Europe’s colonization of Africa had nothing to do with differences between European and African peoples themselves, as white racists assume. Rather, it was due to accidents of geography and biogeography—in particular, to the continents’ different areas, axes, and suites of wild plant and animal species. That is, the different historical trajectories of Africa and Europe stem ultimately from differences in real estate.

[W]hat 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.

History as well as life itself is complicated -- neither life nor history is an enterprise for those who seek simplicity and consistency.

Science is often misrepresented as ‘the body of knowledge acquired by performing replicated controlled experiments in the laboratory.’ Actually, science is something broader: the acquisition of reliable knowledge about the world.

It's striking that Native Americans evolved no devastating epidemic diseases to give to Europeans in return for the many devastating epidemic diseases that Indians received from the Old World.

In much of the rest of the world, rich people live in gated communities and drink bottled water. That's increasingly the case in Los Angeles where I come from. So that wealthy people in much of the world are insulated from the consequences of their actions." [Why Societies Collapse, ABC Local, July 17, 2003]

My two main conclusions are that technology develops cumulatively, rather than in isolated heroic acts, and that it finds most of its uses after it has been invented, rather than being invented to meet a foreseen need.

People often ask, "What is the single most important environmental population problem facing the world today?" A flip answer would be, "The single most important problem is our misguided focus on identifying the single most important problem!

The metaphor is so obvious. Easter Island isolated in the Pacific Ocean — once the island got into trouble, there was no way they could get free. There was no other people from whom they could get help. In the same way that we on Planet Earth, if we ruin our own [world], we won't be able to get help.

Rhino-mounted Bantu shock troops could have overthrown the Roman Empire. It never happened.

Two types of choices seem to me to have been crucial in tipping the outcomes [of the various societies' histories] towards success or failure: long-term planning and willingness to reconsider core values. On reflection we can also recognize the crucial role of these same two choices for the outcomes of our individual lives.

All human societies contain inventive people. It’s just that some environments provide more starting materials, and more favorable conditions for utilizing inventions, than do other environments.

Not until the beginning of the 20th century did Europe's urban populations finally become self-sustaining: before then, constant immigration of healthy peasants from the countryside was necessary to make up for the constant deaths of city dwellers from crowd diseases.

In contrast [to trees and fish], oil, metals, and coal are not renewable; they don't reproduce, sprout, or have sex to produce baby oil droplets or coal nuggets.

Tolstoy meant that, in order to be happy, a marriage must succeed in many different respects: sexual attraction, agreement about money, child discipline, religion, in-laws, and other vital issues.

It invites a search for ultimate causes: why were Europeans, rather than Africans or Native Americans, the ones to end up with guns, the nastiest germs, and steel?

The history of interactions among disparate peoples is what shaped the modern world through conquest, epidemics and genocide. Those collisions created reverberations that have still not died down after many centuries, and that are actively continuing in some of the world's most troubled areas.

We know from our recent history that English did not come to replace U.S. Indian languages merely because English sounded musical to Indians' ears. Instead, the replacement entailed English-speaking immigrants' killing most Indians by war, murder, and introduced diseases, and the surviving Indians' being pressured into adopting English, the new majority language.

Twelve thousand years ago, everybody on earth was a hunter-gatherer; now almost all of us are farmers or else are fed by farmers. The spread of farming from those few sites of origin usually did not occur as a result of the hunter-gatherers' elsewhere adopting farming; hunter-gatherers tend to be conservative.... Instead, farming spread mainly through farmers' outbreeding hunters, developing more potent technology, and then killing the hunters or driving them off of all lands suitable for agriculture.

One way to explain the complexity and unpredictability of historical systems, despite their ultimate determinacy, is to note that long chains of causation may separate final effects from ultimate causes lying outside the domain of that field of science.

...neither life nor history is an enterprise for those who seek simplicity and consistency.

Technology causes problems as well as solves problems. Nobody has figured out a way to ensure that, as of tomorrow, technology won't create problems. Technology simply means increased power, which is why we have the global problems we face today." (Interview, Sierra Magazine, May/June 2005)

The Anasazi did manage to construct in stone the largest and tallest buildings erected in North America until the Chicago steel girder skyscrapers of the 1880s.

Yes, world history is indeed such an onion!

The past was still a Golden Age, of ignorance, while the present is an Iron Age of willful bliss.

Those who study just one country end up understanding no country.

Why you white man have so much cargo and we New Guineans have so little? (asked Yali)

In contrast, once food can be stockpiled, a political elite can gain control of food produced by others, assert the right of taxation, escape the need to feed itself, and engage full-time in political activities.

African and European skulls of half a million years ago were sufficiently similar to skulls of us moderns that they are classified in our species, Homo sapiens, instead

Nations and individuals accept national and individual responsibility to take action to solve the problem, or else deny responsibility by self-pity, blaming others, and assuming the role of victim.

Despite being depicted in innumerable cartoons as apelike brutes living in caves, Neanderthals had brains slightly larger than our own. They were also the first humans to leave behind strong evidence of burying their dead and caring for their sick.

Isn't language loss a good thing, because fewer languages mean easier communication among the world's people? Perhaps, but it's a bad thing in other respects. Languages differ in structure and vocabulary, in how they express causation and feelings and personal responsibility, hence in how they shape our thoughts. There's no single purpose "best" language; instead, different languages are better suited for different purposes. For instance, it may not have been an accident that Plato and Aristotle wrote in Greek, while Kant wrote in German. The grammatical particles of those two languages, plus their ease in forming compound words, may have helped make them the preeminent languages of western philosophy. Another example, familiar to all of us who studied Latin, is that highly inflected languages (ones in which word endings suffice to indicate sentence structure) can use variations of word order to convey nuances impossible with English. Our English word order is severely constrained by having to serve as the main clue to sentence structure. If English becomes a world language, that won't be because English was necessarily the best language for diplomacy.

success is not guaranteed to well-intentioned decent people, nor necessarily denied to evil people.

The whole modern world has been shaped by lopsided outcomes.

What doesn’t kill us makes us stronger.” Winston Churchill’s corresponding quip was “Never let a good crisis go to waste!” A

In areas where there were only hunter-gatherers to begin with, those groups of hunter-gatherers who adopted food production outbred those who didn’t.

In a similar vein, Jared Diamond has observed: “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 almost simultaneously (at least on a time scale of millions of years) precisely and just coincidentally when the first humans arrived.

Besides justifying the transfer of wealth to kleptocrats, institutionalized religion brings two other important benefits to centralized societies. First, shared ideology or religion helps solve the problem of how unrelated individuals are to live together without killing each other—by providing them with a bond not based on kinship. Second, it gives people a motive, other than genetic self-interest, for sacrificing their lives on behalf of others.

To me, the conclusion that the public has the ultimate responsibility for the behavior of even the biggest businesses is empowering and hopeful, rather than disappointing. My conclusion is not a moralistic one about who is right or wrong, admirable or selfish, a good guy or a bad guy. My conclusion is instead a prediction, based on what I have seen happening in the past. Businesses have changed when the public came to expect and require different behavior, to reward businesses for behavior that the public wanted, and to make things difficult for businesses practicing behaviors that the public didn't want. I predict that in the future, just as in the past, changes in public attitudes will be essential for changes in businesses' environmental practices.

(On the beginning of the mid-1990s' genocidal war in Rwanda:) Within six weeks, an estimated 800,000 Tutsi, representing about three-quarters of the Tutsi then remaining in Rwanda, or 11% of Rwanda's total population, had been killed.

In short, we evolved, like other animals, to win the reproduction game. That contest has a single aim, to leave as many descendants as possible.

Despite being depicted in innumerable cartoons as apelike brutes living in caves, Neanderthals had brains slightly larger than our own.

Rigidity or inflexibility can be the result of a previous history of abuse or trauma, or of an upbringing that offered a child no permission to experiment or to deviate from the family norms. Flexibility can come from the freedom of having been allowed to make one’s own choices as one was growing up.

For anyone inclined to caricature environmental history as 'environmental determinism,' the contrasting histories of the Dominican Republic and Haiti provide a useful antidote. Yes, environmental problems do constrain human societies, but the societies' responses also make a difference.

Globalization makes it impossible for modern societies to collapse in isolation, as did Easter Island and the Greenland Norse in the past. Any society in turmoil today, no matter how remote ... can cause trouble for prosperous societies on other continents and is also subject to their influence (whether helpful or destabilizing). For the first time in history, we face the risk of a global decline. But we also are the first to enjoy the opportunity of learning quickly from developments in societies anywhere else in the world today, and from what has unfolded in societies at any time in the past. That's why I wrote this book.

Many of our problems are broadly similar to those that undermined ... Norse Greenland, and that many other past societies also struggled to solve. Some of those past societies failed (like the Greenland Norse) and others succeeded ... The past offers us a rich database from which we can learn in order that we may keep on succeeding.

When you have seen the errors in which you live, you will understand the good that we have done you by coming to your land by order of his Majesty the King of Spain. Our Lord permitted that your pride should be brought low and that no Indian should be able to offend a Christian.

Above all, it seems to me wrongheaded and dangerous to invoke historical assumptions about environmental practices of native peoples in order to justify treating them fairly. ... By invoking this assumption [i.e., that they were/are better environmental stewards than other peoples or parts of contemporary society] to justify fair treatment of native peoples, we imply that it would be OK to mistreat them if that assumption could be refuted. In fact, the case against mistreating them isn't based on any historical assumption about their environmental practices: it's based on a moral principle, namely, that it is morally wrong for one people to dispossess, subjugate or exterminate another people.

It’s neither possible nor desirable for individuals or nations to change completely, and to discard everything of their former identities. The challenge, for nations as for individuals in crisis, is to figure out which parts of their identities are already functioning well and don’t need changing, and which parts are no longer working and do need changing.

Recent discoveries about apes suggest, however, that a gorilla or common chimp stands at least as good a chance of being murdered as the average human.

Thus, Norse society’s structure created a conflict between the short-term interests of those in power, and the long-term interests of the society as a whole.

1,000 out of the world’s 6,000 languages, crammed into an area only slightly larger than that of Texas,

Recreational sex is thus supposed to function as the glue holding a human couple together while they cooperate in rearing their helpless baby.

The past was still a Golden Age, of ignorance, while the present is an Iron Age of wilful blindness.

The earliest preserved examples of the Etruscan and Roman alphabets are also inscriptions on drinking cups and wine containers.

The difference between a kleptocrat and a wise statesman, between a robber baron and a public benefactor, is merely one of degree: a matter of just how large a percentage of the tribute extracted from producers is retained by the elite, and how much the commoners like the public uses to which the redistributed tribute is put.

Thus, Fertile Crescent and eastern Mediterranean societies had the misfortune to arise in an ecologically fragile environment. They committed ecological suicide by destroying their own resource base.

THE IMPORTANCE OF lethal microbes in human history is well illustrated by Europeans’ conquest and depopulation of the New World. Far more Native Americans died in bed from Eurasian germs than on the battlefield from European guns and swords. Those germs undermined Indian resistance by killing most Indians and their leaders and by sapping the survivors’ morale.

Montana would have been better off in the long run if it had never mined copper at all but had just imported it from Chile, leaving the resulting problems to the Chileans! It

the anthropologist Claude Lévi-Strauss put it, ancient writing’s main function was “to facilitate the enslavement of other human beings.

Animal populations that for one reason or another escaped control by predators and parasites have in some cases also escaped their own internal controls on their numbers, multiplied until they damaged their resource base, and occasionally have eaten their way into extinction.

I have often asked myself, "What did the Easter Islander who cut down the last palm tree say while he was doing it?" Like modern loggers, did he shout "Jobs, not trees!"? Or: "Technology will solve our problems, never fear, we'll find a substitute for wood"? Or: "We don't have proof that there aren't palms somewhere else on Easter, we need more research, your proposed ban on logging is premature and driven by fear-mongering"? Similar questions arise for every society that has inadvertently damaged its environment.

Severe problems of overpopulation, environmental impact, and climate change cannot persist indefinitely: sooner or later they are likely to resolve themselves, whether in the manner of Rwanda or in some other manner not of our devising, if we don’t succeed in solving them by our own actions.

Hunter-gatherer societies tend to be relatively egalitarian, to lack full-time bureaucrats and hereditary chiefs, and to have small-scale political organization at the level of the band or tribe. That’s because all able-bodied hunter-gatherers are obliged to devote much of their time to acquiring food.

Pizarro captured Atahuallpa within a few minutes after the two leaders first set eyes on each other. Pizarro proceeded to hold his prisoner for eight months, while extracting history’s largest ransom in return for a promise to free him. After the ransom—enough gold to fill a room 22 feet long by 17 feet wide to a height of over 8 feet—was delivered, Pizarro reneged on his promise and executed Atahuallpa.

food production was indirectly a prerequisite for the development of guns, germs, and steel. Hence geographic variation in whether, or when, the peoples of different continents became farmers and herders explains to a large extent their subsequent contrasting fates.

Every time that an animal eats a plant or another animal, the conversion of food biomass into the consumer’s biomass involves an efficiency of much less than 100 percent: typically around 10 percent. That is, it takes around 10,000 pounds of corn to grow a 1,000-pound cow. If instead you want to grow 1,000 pounds of carnivore, you have to feed it 10,000 pounds of herbivore grown on 100,000 pounds of corn. Even among herbivores and omnivores, many species, like koalas, are too finicky in their plant preferences to recommend themselves as farm animals. As a result of this fundamental inefficiency, no mammalian carnivore has ever been domesticated for food.

It seems logical to suppose that history's pattern reflects innate differences among people themselves. Of course, we're taught that it's not polite to say so in public. We see in our daily lives that some of the conquered peoples continue to form an underclass, centuries after the conquests or slave imports took place. We're told that this too is to be attributed not to any biological shortcomings but to social disadvantages and limited opportunities. Nevertheless, we have to wonder. We keep seeing all those glaring, persistent differences in peoples' status. We're assured that the seemingly transparent biological explanation for the world's inequalities as of A.D. 1500 is wrong, but we're not told what the correct explanation is. Until we have some convincing, detailed, agreed-upon explanation for the broad pattern of history, most people will continue to suspect that the racist biological explanation is correct after all. That seems to me the strongest argument for writing this book.

The history of interactions among disparate peoples is what shaped the modern world through conquest, epidemics, and genocide. Those collisions created reverberations that have still not died down after many centuries, and that are actively continuing in some of the world’s most troubled areas today.

As we shall see, the prerequisites for those developments consisted of several features of human society that determined whether a society would find writing useful, and whether the society could support the necessary specialist scribes. Many

Neanderthals had brains slightly larger than our own. They were also the first humans to leave behind strong evidence of burying their dead and caring for their sick. Yet their stone tools were still crude by comparison with modern New Guineans’ polished stone axes and were usually not yet made in standardized diverse shapes, each with a clearly recognizable function. The

Así pues, tanto las sociedades como los grupos humanos más pequeños pueden tomar decisiones catastróficas por toda una serie secuenciada de razones: la imposibilidad de prever un problema, la imposibilidad de percibirlo una vez que se ha producido, la incapacidad para disponerse a resolverlo una vez que se ha percibido y el fracaso en las tentativas de resolverlos

(4) Modern capitalism is, and the ancient Roman economy was not, organized in a way that made it potentially rewarding to invest capital in technological development. (5) The strong individualism of U.S. society allows successful inventors to keep earnings for themselves, whereas strong family ties in New Guinea ensure that someone who begins to earn money will be joined by a dozen relatives expecting to move in and be fed and supported.

INVENTING A WRITING system from scratch must have been incomparably more difficult than borrowing and adapting one. The first scribes had to settle on basic principles that we now take for granted. For example, they had to figure out how to decompose a continuous utterance into speech units, regardless of whether those units were taken as words, syllables, or phonemes. They

Britain never regained its naval and economic dominance over the world, and it remains notoriously conflicted (“Brexit”) about its role in Europe. But Britain is still among the world’s six richest nations, is still a parliamentary democracy under a figurehead monarch, is still a world leader in science and technology, and still maintains as its currency the pound sterling rather than the euro

Archaeologists studying the rise of farming have reconstructed for us a stage where we made one of the most crucial decisions in human history. Forced to choose between limiting population growth or trying to increase food production, we opted for the latter and ended up with starvation, warfare, and tyranny. The same choice faces us today, with the difference that we now can learn from the past.

The shift from hunting-gathering to farming began only about 11,000 years ago; the first metal tools were produced only about 7,000 years ago; and the first state government and the first writing arose only around 5,400 years ago. “Modern” conditions have prevailed, even just locally, for only a tiny fraction of human history; all human societies have been traditional for far longer than any society has been modern.

Increasingly today, archaeologists are circumventing this problem by a new technique termed accelerator mass spectrometry, which permits radiocarbon dating of tiny samples and thus lets one directly date a single small seed, small bone, or other food residue. In some cases big differences have been found between recent radiocarbon dates based on the direct new methods (which have their own problems) and those based on the indirect older ones.

Still later, after the invention of saddles and stirrups, horses allowed the Huns and successive waves of other peoples from the Asian steppes to terrorize the Roman Empire and its successor states, culminating in the Mongol conquests of much of Asia and Russia in the 13th and 14th centuries A.D. Only with the introduction of trucks and tanks in World War I did horses finally become supplanted as the main assault vehicle and means of fast transport in war. Arabian and Bactrian camels played a similar military role within their geographic range. In all these examples, peoples with domestic horses (or camels), or with improved means of using them, enjoyed an enormous military advantage over those without them.

• “To us today, it is tempting to ask why societies with early writing systems accepted the ambiguities that restricted writing to a few functions and a few scribes. But even to pose that question is illustrate the gap between ancient perspectives and our own expectations of mass literacy. The intended restricted uses of early writing provided a positive disincentive for devising less ambiguous writing systems. The kings and priests of ancient Sumer wanted writing to be used by professional scribes to recorded numbers of sheep owed in taxes, not by the masses to write poetry and hatch plots. As the anthropologist Claude Levi-Strauss put it, ancients writing’s main function was “to facilitate the enslavement of other human beings.” Personal uses of writing by nonprofessionals came only much later, as writing systems grew simpler and more expressive

Thanks to this availability of suitable wild mammals and plants, early peoples of the Fertile Crescent could quickly assemble a potent and balanced biological package for intensive food production. That package comprised three cereals, as the main carbohydrate sources; four pulses, with 20—25 percent protein, and four domestic animals, as the main protein sources, supplemented by the generous protein content of wheat; and flax as a source of fiber and oil (termed linseed oil: flax seeds are about 40 percent oil). Eventually, thousands of years after the beginnings of animal domestication and food production, the animals also began to be used for milk, wool, plowing, and transport. Thus, the crops and animals of the Fertile Crescent's first farmers came to meet humanity's basic economic needs: carbohydrate, protein, fat, clothing, traction, and transport.

Still another factor is compatibility with vested interests. This book, like probably every other typed document you have ever read, was typed with a QWERTY keyboard, named for the left-most six letters in its upper row. Unbelievable as it may now sound, that keyboard layout was designed in 1873 as a feat of anti-engineering. It employs a whole series of perverse tricks designed to force typists to type as slowly as possible, such as scattering the commonest letters over all keyboard rows and concentrating them on the left side (where right-handed people have to use their weaker hand). The reason behind all of those seemingly counterproductive features is that the typewriters of 1873 jammed if adjacent keys were struck in quick succession, so that manufacturers had to slow down typists. When improvements in typewriters eliminated the problem of jamming, trials in 1932 with an efficiently laid-out keyboard showed that it would let us double our typing speed and reduce our typing effort by 95 percent. But QWERTY keyboards were solidly entrenched by then. The vested interests of hundreds of millions of QWERTY typists, typing teachers, typewriter and computer salespeople, and manufacturers have crushed all moves toward keyboard efficiency for over 60 years.

The U.S. has so many rules and regulations, because of fear of being sued, that kids give up on the opportunity for personal exploration. A pool has to be fenced so that it’s not an ‘attractive nuisance.’ Most New Guineans don’t have pools, but even the rivers that we frequented didn’t have signs saying ‘Jump at your own risk,’ because it’s obvious. Why would I jump unless I’m prepared for the consequences? Responsibility in the U.S. has been taken from the person acting and has been placed on the owner of the land or the builder of the house. Most Americans want to blame someone other than themselves as much as possible. In New Guinea I was able to grow up, play creatively, and explore the outdoors and nature freely, with the obligatory element of risk, however well managed, that is absent from the average risk-averse American childhood. I had the richest upbringing possible, an upbringing inconceivable for Americans.

There is nothing new about prophecies to the effect that the end of the world is near if we do not repent. What is new is that such a prophecy is now true, for two obvious reasons. First, nuclear weapons give us the means to wipe ourselves out quickly: no humans possessed this means before. Second, we already appropriate about forty per cent of the Earth’s net productivity (that is, the net energy captured from sunlight). With the world’s human population now doubling every forty-one years, we will soon have reached the biological limit to growth, at which point we will have to start fighting each other in deadly earnest for a slice of the world’s fixed pie of resources. In addition, given the present rate at which we are exterminating species, most of the world’s species will become extinct or endangered within the next century, but we depend on many species for our own life support.

Finland’s crisis (Chapter 2) exploded with the Soviet Union’s massive attack upon Finland on November 30, 1939. In the resulting Winter War, Finland was virtually abandoned by all of its potential allies and sustained heavy losses, but nevertheless succeeded in preserving its independence against the Soviet Union, whose population outnumbered Finland’s by 40 to 1. I spent a summer in Finland 20 years later, hosted by veterans and widows and orphans of the Winter War. The war’s legacy was conspicuous selective change that made Finland an unprecedented mosaic, a mixture of contrasting elements: an affluent small liberal democracy, pursuing a foreign policy of doing everything possible to earn the trust of the impoverished giant reactionary Soviet dictatorship. That policy was considered shameful and denounced as “Finlandization” by many non-Finns who failed to understand the historical reasons for its adoption. One of the most intense moments of my summer in Finland unfolded when I ignorantly expressed similar views to a Winter War veteran, who replied by politely explaining to me the bitter lessons that Finns had learned from being denied help by other nations.

(1) Risk-taking behavior, essential for efforts at innovation, is more widespread in some societies than in others. (2) The scientific outlook is a unique feature of post-Renaissance European society that has contributed heavily to its modern technological preeminence. (3) Tolerance of diverse views and of heretics fosters innovation, whereas a strongly traditional outlook (as in China’s emphasis on ancient Chinese classics) stifles it. (4) Religions vary greatly in their relation to technological innovation: some branches of Judaism and Christianity are claimed to be especially compatible with it, while some branches of Islam, Hinduism, and Brahmanism may be especially incompatible with it.

In particular, while natural selection favors both males and females that leave many offspring, the best strategy for doing so may be different for fathers and mothers. That generates a built-in conflict between the parents, a conclusion that all too many humans don’t need scientists to reveal to them. We make jokes about the battle of the sexes, but the battle is neither a joke nor an aberrant accident of how individual father or mothers behave on particular occasions. It is indeed perfectly true that behavior that is in a male’s genetic interests may not necessarily be in the interests of his female co-parent, and vice versa. That cruel fact is one of the fundamental causes of human misery.

Suppose that an archaeologist who had visited us from outer space were trying to explain human history to his fellow spacelings. The visitor might illustrate the results of his digs by a twenty-four-hour clock on which one hour of clock-time represents 100,000 years of real past time. If the history of the human race began at midnight, then we would now be almost at the end of our first day. We lived as hunter-gatherers for nearly the whole of that day, from midnight through dawn, noon, and sunset. Finally, at 11:54 pm we adopted agriculture. In retrospect, the decision was inevitable, and there is now no question of turning back. But as our second midnight approaches, will the present plight of African peasants gradually spread to engulf all of us? Or, will we somehow achieve those seductive blessings that we imagine behind agriculture’s glittering facade, and that have so far eluded us except in mixed form?

four suggested explanations are ideological, rather than economic or organizational: (1) Risk-taking behavior, essential for efforts at innovation, is more widespread in some societies than in others. (2) The scientific outlook is a unique feature of post-Renaissance European society that has contributed heavily to its modern technological preeminence. (3) Tolerance of diverse views and of heretics fosters innovation, whereas a strongly traditional outlook (as in China’s emphasis on ancient Chinese classics) stifles it. (4) Religions vary greatly in their relation to technological innovation: some branches of Judaism and Christianity are claimed to be especially compatible with it, while some branches of Islam, Hinduism, and Brahmanism may be especially incompatible with it.

As on Easter Island and at Chaco Canyon, Maya peak population numbers were followed swiftly by political and social collapse. Paralleling the eventual extension of agriculture from Easter Island's coastal lowlands to its uplands, and from the Mimbres floodplain to the hills, Copan's inhabitants also expanded from the floodplain to the more fragile hill slopes, leaving them with a larger population to feed when the agricultural boom in the hills went bust. Like Easter Island chiefs erecting ever larger statues, eventually crowned by pukao, and like Anasazi elite treating themselves to necklaces of 2,000 turquoise beads, Maya kings sought to outdo each other with more and more impressive temples, covered with thicker and thicker plaster-reminiscent in turn of the extravagant conspicuous consumption by modern American CEOs. The passivity of Easter chiefs and Maya kings in the face of the real big threats to their societies completes our list of disquieting parallels.

A hunter-gatherer mother who is shifting camp can carry only one child, along with her few possessions. She cannot afford to bear her next child until the previous toddler can walk fast enough to keep up with the tribe and not hold it back. In practice, nomadic hunter-gatherers space their children about four years apart by means of lactational amenorrhea, sexual abstinence, infanticide, and abortion. By contrast, sedentary people, unconstrained by problems of carrying young children on treks, can bear and raise as many children as they can feed. The birth interval for many farm peoples is around two years, half that of hunter-gatherers. That higher birthrate of food producers, together with their ability to feed more people per acre, lets them achieve much higher population densities than hunter-gatherers.

write these pages, Japan and the U.S. are still practicing widespread selective denial of major problems. Japan currently acknowledges some problems (its large government debt and aging population), and incompletely acknowledges the issue of Japanese women’s role. But Japan still denies other problems: its lack of accepted alternatives to immigration for solving its demographic difficulties; the historical causes of Japan’s tense relations with China and Korea; and denial that Japan’s traditional policy of seeking to grab overseas natural resources rather than to help manage them sustainably is now outdated. The U.S., as I write, is still in widespread denial of our own major problems: political polarization, low voter turnout, obstacles to voter registration, inequality, limited socio-economic mobility, and decreasing government investment in public goods.

Perhaps the most important single step in the whole history of writing was the Sumerians’ introduction of phonetic representation, initially by writing an abstract noun (which could not be readily drawn as a picture) by means of the sign for a depictable noun that had the same phonetic pronunciation. For instance, it’s easy to draw a recognizable picture of arrow, hard to draw a recognizable picture of life, but both are pronounced ti in Sumerian, so a picture of an arrow came to mean either arrow or life. The resulting ambiguity was resolved by the addition of a silent sign called a determinative, to indicate the category of nouns to which the intended object belonged. Linguists term this decisive innovation, which also underlies puns today, the rebus principle.

ONLY a few areas of the world developed food production independently, and they did so at widely differing times. From those nuclear areas, hunter-gatherers of some neighboring areas learned food production, and peoples of other neighboring areas were replaced by invading food producers from the nuclear areas—again at widely differing times. Finally, peoples of some areas ecologically suitable for food production neither evolved nor acquired agriculture in prehistoric times at all; they persisted as hunter-gatherers until the modern world finally swept upon them. The peoples of areas with a head start on food production thereby gained a head start on the path leading toward guns, germs, and steel. The result was a long series of collisions between the haves and the have-nots of history.

Like all animal species (including humans), plants must spread their offspring to areas where they can thrive and pass on their parents’ genes. Young animals disperse by walking or flying, but plants don’t have that option, so they must somehow hitchhike. While some plant species have seeds adapted for being carried by the wind or for floating on water, many others trick an animal into carrying their seeds, by wrapping the seed in a tasty fruit and advertising the fruit’s ripeness by its color or smell. The hungry animal plucks and swallows the fruit, walks or flies off, and then spits out or defecates the seed somewhere far from its parent tree. Seeds can in this manner be carried for thousands of miles. It may come as a surprise to learn that plant seeds can resist digestion by your gut and nonetheless germinate out of your feces. But any adventurous readers who are not too squeamish can make the test and prove it for themselves. The seeds of many wild plant species actually must pass through an animal’s gut before they can germinate. For instance, one African melon species is so well adapted to being eaten by a hyena-like animal called the aardvark that most melons of that species grow on the latrine sites of aardvarks.