Summary: Collapse

The GIST

Collapse by Jared Diamond, subtitled How Societies Choose to Fail or Succeed, asks one of the most unsettling questions history can pose: why do some societies, even rich and accomplished ones, fall apart, while others in equally hard places endure for centuries? Diamond began as a physiologist, became a geography professor at UCLA, and has spent decades studying birds in New Guinea. His earlier book, the Pulitzer Prize-winning Guns, Germs, and Steel, asked why some societies came to dominate. This 2005 follow-up, close to six hundred pages long, turns the question over and asks why some disappear.

His answer is that environmental factors are often decisive, but that collapse is never simply fate. The "choose" in the subtitle is the point. He defines collapse as "a drastic decrease in human population size and/or political/economic/social complexity, over a considerable area, for an extended time," and then walks through the ruins of Easter Island, the Maya cities and the Norse farms of Greenland, setting each failure beside a society that faced something similar and survived. It matters now, he argues, because the old escape hatch is gone: "Globalization makes it impossible for modern societies to collapse in isolation, as did Easter Island and the Greenland Norse in the past."

The Big Ideas

Five factors, and why the story starts in Montana

The book opens with two dairy farms. One is the thriving Huls Farm in modern Montana. The other is Gardar, the manor farm of the Norse bishop in Greenland, abandoned more than five hundred years ago. Its barn and cathedral walls still stand, well enough preserved that Diamond could count the individual cow stalls, but there is no owner left to ask about it. He reaches for Shelley's "Ozymandias," whose opening lines are the book's epigraph. The unspoken question is whether a prosperous modern farm could one day be the same kind of ruin.

To answer it he offers a five-point framework. A society can be undone by environmental damage such as deforestation, soil erosion or pollution; by climate change; by hostile neighbours; by the loss of support from friendly neighbours; and by the way it responds to its own problems. The first four vary from case to case. The fifth always matters. His method is comparison, a series of natural experiments that set failures beside similar societies that lasted.

He begins not with a ruin but with Montana, where he has spent summers in the Bitterroot Valley for decades. Montana looks rich, beautiful and unspoiled, yet it lives with toxic mining waste, forest fires and logging troubles, salty soils, water shortages and invasive species. He picks it because its problems are real but still mild by First World standards, and because he knows the people: through the stories of individual Montanans he shows the clashes over property rights, regulation, and old-timers against wealthy newcomers that he will find again and again in societies that failed.

The past: islands, deserts and jungle cities

Easter Island is the purest case of environmental damage acting alone. Polynesian settlers gradually cleared the island's forest, including a giant palm. Rival chiefs competed to raise ever-larger stone statues, the moai, which needed timber and rope to move, and rats ate the trees' seeds. With the forest gone there was no wood for seagoing canoes or for fires, and the soil washed away. Society dissolved into warfare, the statues were toppled, and there are reports of cannibalism. Diamond wonders what could have been going through the mind of the islander who felled the last tree, and he treats the island as a metaphor for Earth itself: isolated, with nowhere to flee.

Pitcairn and Henderson Islands show a different danger, the loss of friendly neighbours. Both islands damaged their own environments, but the fatal blow came when their major trading partner, Mangareva, collapsed for environmental reasons of its own. Their last inhabitants died out completely.

In the American Southwest, the Anasazi show what happens when environmental damage and population growth meet a changing climate. Tree-ring dating lets the story be told almost year by year, and the ancient nests of packrats preserve plant remains that reveal how the land around Chaco Canyon was stripped of trees. The canyon was abandoned around the twelfth century, after drought struck a society already stretched to its limit.

The Maya, whom Diamond calls "the most advanced Native American society and the quintessential romantic mystery of cities covered by jungle," tell a similar tale on a grander scale. Using Copán as his main example, he blends several causes: a population that outgrew its resources, cleared hillsides and eroded soil, repeated droughts, constant warfare, and kings more absorbed in monuments and status than in long-term trouble.

Norse Greenland: the closest thing to a controlled experiment

The longest and most admired case fills three chapters. In Greenland all five factors were at work: environmental damage, a cooling climate, fading contact with Norway, growing hostility with the Inuit, and the Norse settlers' own political, economic, social and cultural habits.

What makes it so powerful is the comparison built into it. Two peoples shared the same island, the Norse and the Inuit, and only one survived. A historian once joked that the Norse came to Greenland, it got cold, and then they died. But the Inuit came too, stayed, and lived. In Diamond's telling, the Norse clung to a European, Christian identity. They kept raising cattle in a marginal climate, poured their wealth into churches and the walrus-ivory trade, and declined to borrow the tools that kept the Inuit alive, the kayaks, harpoons and seal hunting. He even argues they seem to have had a taboo against eating fish. When the Little Ice Age arrived and the ships from Norway stopped coming, those choices left them exposed, and the settlements died out in the 1400s.

He widens the frame to the other North Atlantic colonies founded by Norse settlers, asking why the Orkney Norse thrived, and why Iceland became a standout success, while their Greenland cousins vanished. The lesson he draws is the book's thesis in miniature: "even in a harsh environment, collapse isn't inevitable but depends on a society's choices."

Two opposite paths to success

Diamond is careful to show that societies also get it right, and that they do so in two quite different ways. The first is bottom-up. On tiny Tikopia, islanders controlled their population, gave up their pigs, and farmed the whole island like an orchard. In the New Guinea highlands, farmers planted casuarina trees to restore their wood supply. These are small societies where everyone can see the whole problem.

The second is top-down. In Tokugawa Japan, shoguns alarmed by deforestation built a system of scientific forest management in the 1600s and 1700s. A strong, far-sighted ruler can do what a village does, on the scale of a nation.

The same forces in the modern world

Part Three brings the argument into living memory. In Rwanda, extremist Hutu leaders launched the 1994 genocide that killed 800,000 Tutsi, four-fifths of their number. Diamond argues that more than ethnic hatred was at work. Rwanda's population density was triple that of Nigeria and ten times that of neighbouring Tanzania, and studies of the commune of Kanama show Hutu killing Hutu over land. He writes that "modern Rwanda illustrates a case where Malthus's worst-case scenario does seem to have been right."

The island of Hispaniola offers a modern natural experiment: the Dominican Republic, still largely forested, beside Haiti, heavily deforested. Diamond traces the difference to history, colonial policy, rainfall, and the decisions of leaders, including the dictators Trujillo and Balaguer, who protected forests. The contrast, he says, gives the clearest illustration that a society's fate lies in its own hands.

China, his "lurching giant," faces problems of air, water, soil, spreading desert and vanishing wildlife on a scale that makes its choices matter to the whole planet. Australia, a wealthy country sitting on old, infertile soils, has been "mined": its soils, forests and fisheries used up like a resource that will not renew, in part because settlers imported British values and farming methods into a land that could not sustain them. He also sees Australians beginning to rethink those values.

Why societies make disastrous decisions

The conceptual heart of the book is a roadmap of how groups of intelligent people walk into catastrophe. First, they may fail to anticipate a problem, because they have never met it before or reason by false analogy, as when the Norse farmed Greenland as if it were Norway. Second, they may fail to perceive a problem that has already arrived. It may be invisible, like the nutrients in soil, or too slow to notice. Diamond gives this two memorable names: creeping normalcy, when a slow trend hides behind year-to-year ups and downs, and landscape amnesia, when people forget how different the land once looked.

Third, they may see the problem and fail to try to solve it. Sometimes this is "rational" bad behaviour, when a narrow group profits at everyone else's expense or when elites are shielded from the consequences of their own decisions. Sometimes it is "irrational": clinging to cherished values that have become harmful, or sacrificing the long term for the short. Fourth, they may try and fail anyway, because the problem is too hard, the cure too costly, or the effort too late.

Diamond applies the same cool logic to big business. Looking at oil, mining, coal, logging and fishing, he argues that companies behave well or badly according to their incentives, which means the final responsibility rests with the public: consumers and regulators.

Putting It to Work

• Check all five factors. When judging a society's prospects, including your own, look beyond the environment to climate, enemies, trading partners and, above all, how the society is responding.
• Beware slow change. Creeping normalcy and landscape amnesia mean the gravest problems may be the ones that never produce a single alarming day. Long records and long memories are a defence.
• Watch who is insulated. Trouble deepens when the people making decisions do not suffer their consequences. Diamond's image for the alternative is the Dutch polder, land reclaimed from the sea, where everyone must cooperate because everyone would drown together.
• Be willing to rethink core values. The Greenland Norse held on to an identity that no longer fit their surroundings. Diamond names two choices that proved crucial for societies that survived: courageous long-term planning and the willingness to reconsider deeply held values.
• Use your leverage as a customer and citizen. If companies follow incentives, then public pressure, regulation and certification schemes such as the Forest Stewardship Council and the Marine Stewardship Council are how those incentives change.
• Hold on to cautious optimism. Diamond lists about a dozen grave environmental problems, from habitat loss and overfishing to water, soil, toxic chemicals and greenhouse gases, and he rejects easy reassurances such as the claim that technology will take care of it. But the problems are of our own making, so they are ours to solve.

Who Should Read It

This is a book for readers who love big-picture history and want to understand the present through the past: anyone curious about archaeology's great mysteries, worried about the environment, or interested in how groups make decisions. Reviewers praised its clarity and the way it turns the history of societies into something close to an adventure story, and the paired comparisons, the Norse beside the Inuit and Haiti beside the Dominican Republic, are its high points. It is long, and some readers find the detail heavy, the explanations similar from case to case and the conclusions bolder than the evidence allows. Those who settle in will come away seeing ruins, and the evening news, differently.

This has been a summary of Collapse by Jared Diamond, giving you the GIST so you can decide if you want the REST.