Book SummarySapiens, by Yuval Noah Harari

1-Page Summary1-Page Book Summary of Sapiens

In Sapiens, Yuval Noah Harari uses concepts from physics, chemistry, biology, and history to tell the story of us, Homo sapiens.

Our history is punctuated by four major revolutions: The Cognitive Revolution, the Agricultural Revolution, the Scientific Revolution, and the Industrial Revolution. We’ll look at each revolution and how it dramatically redirected the course of human history.

The Cognitive Revolution

2.5 million years ago, Homo sapiens was just one of eight human species. The first major revolution for Sapiens was the Cognitive Revolution 70,000 years ago. Before that point, Sapiens weren’t particularly special and weren’t superior to the other seven human species. The Cognitive Revolution involved the development of three new abilities, all related to language, that helped Homo sapiens outpace their fellow humans.

Ability #1: Flexible Language

One reason the language of Sapiens was different was that it was more complex. Rather than communicating simple ideas the way green monkeys do (“Careful! A lion!” or “Careful! An eagle!”), the language of Sapiens could warn someone about a lion, describe its location, and plan how to deal with it. This allowed them to plan and follow through on complex actions like avoiding predators and working together to trap prey.

Ability #2: Gossip

A second distinction of the Sapiens language was its ability to convey gossip. We think of gossip as a bad thing, but using language to convey information about other people is a way to build trust. Trust is critical for social cooperation, and cooperation gives you an advantage in the struggle to survive and pass on your genes. Sapiens could form groups of up to 150 people. They didn’t need to know every group member personally to trust them. In a battle, a small group of Neanderthals was no match for a group of 150 Sapiens.

Ability #3: Fictions

A third benefit of the Sapiens’ language was how it was used to create fictions, also known as “social constructs” or “imagined realities.”

Being able to communicate information about things that don’t exist doesn’t seem like an advantage. But Sapiens seem to be the only animals who have this ability to discuss things that don’t have a physical presence in the world, like money, human rights, corporations, and God.

Collective Fictions

In and of itself, imagining things that don’t exist isn’t an asset—you won’t aid your chances of survival if you go into the forest looking for ghosts rather than berries and deer.

What’s important about the ability to create fictions is the ability to create collective fictions, fictions everyone believes. These collective myths allow people who’ve never met and otherwise would have nothing in common to cooperate under shared assumptions and goals.

Although imagined, these myths are crucial. Without collective fictions, the systems built on them collapse. And as we’ll see, most of our modern systems are built on these imagined realities. These myths are powerful, and the fact that they’re not rooted in objective reality doesn’t undermine them.

Collective fictions allowed early Sapiens to cooperate within extremely large groups of people, most of whom they’d never met, and it rapidly changed their social behavior.

The Agricultural Revolution

About 10,000 years ago, between 9500 and 8500 BC, Sapiens started shifting from forager lifestyles to a life revolving around agriculture. This was the Agricultural Revolution. It was so successful for our species that we went from 5-8 million foragers in 10,000 BC to 250 million farmers by the first century AD.

The move from foraging to agriculture wasn’t necessarily a conscious choice. Rather, it was a gradual process of small, seemingly insignificant changes. Let’s see how those small changes add up to a monumental revolution.

The Spread of Wheat

18,000 years ago, the last ice age retreated, increasing rainfall. This was great for wheat and other grains, which started to spread. Because there was more wheat, people started eating more of it, taking it back to their campsites to grind and cook. On the way to the campsite, some of the small grains were sprinkled along the path, helping the spread of wheat.

Humans burned the forests to create clearings that attracted animals. This also cleared the area of large trees and bushes that would have competed with the wheat for sunlight and water. Where wheat prospered, nomads would settle for a few weeks, enjoying the plenty. A few weeks turned into a few more, and over generations, these areas became permanent settlements.

People started storing grain for later and invented stone scythes, pestles, and mortars. Because they saw that wheat grew better when it was buried deep in the soil rather than sprinkled on top, humans began to hoe and plow the fields. Weeding, watering, and fertilizing followed. With all this time spent on tending the wheat, there was less time to hunt and gather. Sapiens had become farmers.

The move toward farming wasn’t an obvious benefit, since it led to a number of drawbacks.

• Agriculture was much harder than foraging and hunting for food, and it left farmers more vulnerable to disease and hunger.
• Farmers also had a less nutritious diet than foragers due to its lack of variety.
• When agriculture succeeded, all the extra food they grew resulted in a population boom. More people meant closer living quarters, leading to disease epidemics. Child mortality soared.

Most of the surplus went to the elite, and they probably did live better lives than their ancestors. But...

Sapiens Summary Part I: Revolution of the Mind | Chapter 1: An Insignificant Species

In Sapiens, Yuval Noah Harari uses concepts from physics, chemistry, biology, and history to tell the story of us, Homo sapiens.

Our history is punctuated by four major revolutions: The Cognitive Revolution, the Agricultural Revolution, the Industrial Revolution, and the Scientific Revolution. Part I (Chapters 1-4) explores the Cognitive Revolution and the events leading up to it.

We’ll look at each revolution and how it dramatically redirected the course of human history, but to understand these upheavals, we need to go back to a time when Homo sapiens was just one of multiple human species (and not a very distinguished species, at that).

Multiple Human Species

We think of our own species as the only humans, distinguished from and superior to every other species on earth. But when we, Homo sapiens, arrived on the scene 2.5 million years ago, we weren’t anything special. We existed in the middle of the food chain, as often prey as we were predators, and we weren’t even the only humans.

The Eight Human (Homo) Species

Humans evolved in East Africa from a genus of apes. These early humans settled all over the world, and as the climates and conditions...

Sapiens Summary Chapter 2: Language, Gossip, and Imagined Realities

The first major revolution for Sapiens was the Cognitive Revolution. Before that point, Sapiens weren’t particularly special among animals. Over time, they had evolved the abilities to cross oceans and invent things like bows and arrows, sewing needles, oil lamps, and art. They had become humans that we’d recognize today, with our level of intelligence and creativity. But until the Cognitive Revolution of 70,000 years ago, they weren’t superior to other humans.

The Cognitive Revolution

Although the use of fire hastened Sapiens’ ascent, it was the Cognitive Revolution that ultimately distinguished Sapiens from other humans.

What caused the Cognitive Revolution? No one’s really sure, but it was probably a chance gene mutation that changed the way the brain was wired.

The Cognitive Revolution involved the development of three new abilities, all related to language, that helped Homo sapiens outpace their fellow humans.

Ability #1: Flexible Language

Their language gave Sapiens a huge advantage over their fellow animals, including their fellow humans.

Language itself isn’t particularly special—apes and monkeys communicate vocally, as do elephants, whales, and...

Sapiens Summary Chapter 3: The Life of a Forager

We’ve only been working in offices and, before that, as farmers and herders, for the last 12,000 years. For hundreds of thousands of years before that, the majority of our species’ history, we were foragers.

We Don’t Know Much About Foragers

Because foragers moved every week, sometimes every day, they had few personal possessions. They only had what they could carry themselves, without the aid of wagons or pack animals. Consequently, Sapiens during the period between the Cognitive Revolution and the Agricultural Revolution left few artifacts. Dependence on the few artifacts discovered creates an incomplete and even misleading picture of our ancestors.

It’s also hard to talk about how early Sapiens lived because there was no single way of life (as there isn’t now). Still, attempting to piece together how our ancestors lived from 70,000 to 12,000 years ago can give us insight into our modern society.

The Few Things We’re Pretty Sure Of

• There weren’t many humans. The whole human population was smaller than the number of people living in Cairo today.
• Sapiens lived in bands of up to several hundred individuals.
• **Neighboring bands...

Sapiens Summary Chapter 4: Human Migration and Mass Extinction

Before the Cognitive Revolution, humans lived solely on the landmass of Afro-Asia and a few surrounding islands. They didn’t alter these environments and ecosystems dramatically. Animals on the African and Asia continents had evolved alongside humans and knew how to avoid them and hold their own.

But as humans migrated to other parts of the world, parts wholly unprepared to face the threat of human beings, this would change. This chapter looks at the ecological impact of human migration to Australia, America, and then the rest of the world.

Human-Caused Extinction in Australia

Somehow, humans managed to cross the sea barrier after the Cognitive Revolution. No one’s really sure how, but the best theory is that Sapiens in Indonesia learned how to build boats and managed to reach Australia. Human colonization of Australia is one of the most important events in history, on par with the moon landing. It was here that Sapiens rose to the top of the food chain and became the deadliest species in Earth’s history.

Before the arrival of humans, Australia was home to many large animals that sound mythical to modern ears. They included:

• A kangaroo that was six feet tall...

Sapiens Summary Part II: Revolution of the Land | Chapter 5: Farming

Part Two details the second major upheaval of the Sapiens’ way of life: The Agricultural Revolution. Chapter 5 charts the advent of farming while also introducing a concept that we’ll return to throughout the rest of the book: the idea that success isn’t the same thing as happiness.

Sometimes, our evolutionary success is at odds with our well-being and happiness. Evolutionary success is pretty easy to judge and quantify—the more individuals of your species that survive, and the more copies of your DNA in existence, the more successful you are. Happiness, on the other hand, is harder to quantify. (We’ll spend a whole chapter, Chapter 19, breaking down the meaning and theories of happiness.)

Another recurrent theme, explored in the previous chapter, is that Sapiens isn’t the only species that matters. As we examine their history, we should also look at how the success of Sapiens affected other species.

The Success (and Suffering) of People During the Agricultural Revolution

About 10,000 years ago, between 9500 and 8500 BC, Sapiens started shifting from forager lifestyles to a life revolving around agriculture. This was the Agricultural Revolution. It was so...

Sapiens Summary Chapter 6: The Rise of Anxiety and the Political Order

Prior to the Agricultural Revolution, people didn’t live in houses. They roamed, following herds of animals or finding areas of more plant growth. With domestication of plants and animals, humans began living in houses (the word “domesticate” comes from the Latin for “house”).

The home, a new concept, measured a few dozen feet. It represented a separation from the rest of your band. Whereas nomads lived together, with the development of the house we became more individualistic, self-centered animals.

We also separated ourselves from the rest of nature. We cleared forests and fields, planted trees and proclaimed them “ours,” fenced off “our” land, and eliminated pesky weeds and animals. We were the masters of our individual universes, but this came with a lot of responsibility and the anxiety that attends it.

Anxieties About the Future

Nomadic foragers hadn’t given too much thought to what the future had in store. They were mostly focused on what they did and had in the present. There was little they could do to influence future events, so they didn’t worry about it. This saved them a lot of anxiety.

But** the Agricultural Revolution required a focus on the...

Sapiens Summary Chapter 7: The Invention of Writing

The social orders and cooperative systems of some species are maintained because the information for their maintenance is encoded in their DNA. For example, the behavior that makes a female bee fulfill her role as either a worker or queen is programmed into her genes.

But imagined systems aren’t encoded in our DNA, so we have to memorize the roles and behaviors they require. This worked for Sapiens for a while, but our systems became complex and required more information than one brain could hold.

Limits of the Brain

The brain isn’t good at storing information. It has a limited storage capacity and it doesn’t last forever. When humans die, so do their brains. All the information contained in a single brain is lost. Transmitting information to other brains is possible, but how much can be transmitted is limited, and what is transmitted may be muddied and distorted.

Further, the brain has evolved to store some types of information better than others. We’re good at remembering information about the qualities and behavior patterns of plants and animals, information about topography, and information about social ties. This information was crucial to the survival of...

Sapiens Summary Chapter 8: The Imagined Reality of Justice

As we’ve seen, Sapiens evolve genetically to organize themselves into large groups, so they formed societies through the use of imagined orders and writing.

Imagined Hierarchies

We require these imagined orders to function, but they’re not equitable or impartial. They result in systems that discriminate some and privilege others. In fact, there’s no known society that doesn’t discriminate.

Hierarchies have a purpose: they let us know how to interact with others without actually knowing them, which in theory is more efficient and lets us function in large societies. For instance, a woman selling flowers doesn’t know all her customers personally. To figure out how to divvy up her energy and time, she uses the social cues dictated by each person’s place in the hierarchy—such as the way he’s dressed, his age, and, often, his skin color—to determine who is the executive, likely to buy a lot of expensive roses, and who is the messenger boy, only able to afford daisies.

Almost all hierarchies are imagined (we’ll look at a possible exception, the hierarchy of males and females, at the end of this chapter). But we usually claim that they’re natural. For example,...

Sapiens Summary Part III: The Creation of a Global Society | Chapter 9: The Direction of Cultural Evolution

Culture is the “network of artificial instincts” that connect us, myths so ingrained that we take them for granted. As we’ve seen, these myths allow us to cooperate and thrive in large groups.

Cultures aren’t static. They may have values and norms based on tradition, but they’re still in constant flux. Chapter 9 looks at how cultures evolve, whether that evolution is linear, and where our cultures are headed.

The Value of Cognitive Dissonance

Cultural changes may be a result of pressures from external factors like the environment or neighboring cultures. Or they may be the product of internal factors like the contradictions inherent in every culture. Psychologists call these contradictions cognitive dissonance. Cognitive dissonance occurs when we hold two or more thoughts or beliefs that are incompatible with one another.

Every single culture contains contradictions that lead to cognitive dissonance, and they’re actually beneficial. This is because cultures continually attempt to resolve and reconcile the contradictions in their myths. This leads to change, allowing for a more creative and dynamic species. Contradictions in our beliefs force us to examine them and...

Sapiens Summary Chapter 10: The Monetary Order

The first unifier of humankind is money. Money is a relatively recent invention. Hunter-gatherers didn’t have money because they found, killed, or produced everything they needed to survive. They shared what they had in their small bands in return for favors. For instance, if you gave your band member a piece of your meat, you expected her to give you some of her berries in return.

Economies of Favors and Bartering

Even at the start of the Agricultural Revolution, there was little need for money. Villages were self-sufficient, and what they couldn’t provide for themselves they bartered for in other villages. Although some individuals had expertise in an area like shoemaking or medicine, villages were too small for anyone to have a full-time occupation other than farming.

This changed with the growth of societies and improving transportation. In large cities where there were many people in need of your goods or services, it made sense to specialize in shoemaking, medicine, law, or carpentry, and depend on the reciprocity of your customers for your other needs. Specialization also allowed individuals to grow their expertise, which benefited the entire community.

The...

Sapiens Summary Chapter 11: The Imperial Order

Money has brought the disparate worlds on Earth into one global community, but the market doesn’t always win. We can’t view human history solely through the lense of economy. While gold and silver had a huge impact in shaping our world, steel did as well.

The second unifier of humankind is empire. An empire is a political system that meets 2 requirements:

1. It rules over a large number of people living in distinct areas and of distinct cultural heritages. For example, the Roman Empire was comprised of diverse cultural communities in Europe, North Africa, and parts of Asia.

2. It can take in increasingly more territories without changing, in any fundamental way, the overall functioning, structure, and identity of the system. This distinction is a little subtler. Let’s compare Great Britain today and the British Empire of the past. Great Britain has definite borders. To extend or alter them would change Great Britain’s basic structure and identity. Great Britain isn’t an empire. In contrast, a century ago, the British Empire encompassed territories all over the world and still retained its British identity. The fact that it could maintain its identity while expanding...

Sapiens Summary Chapter 12: The Religious Order

The third unifier of humankind is religion.

Today, we often think of religion as something that divides rather than unites. Yet religion has a crucial role in supporting our other imagined orders, orders that have led to our success as a species.

Because the social orders on which our societies are founded are imaginary, they’re fragile. Religion’s role is to give “superhuman legitimacy” to these orders, making them hard to challenge. This makes social orders more stable.

But not all religions unify, and not all belief systems are religions. Let’s look first at the definition and requirements that make a belief system a religion, and then we’ll look at the additional requirements that give particular religions their unifying function.

To be a religion, a system has to meet two requirements:

1. The system has to be predicated on the belief in a “superhuman” order. As used here, “superhuman” is defined as “not the product of human actions.” For instance, professional soccer shares a lot in common with religion: it contains rituals, rites, and laws. But because these rituals and laws are determined by humans (in this case, FIFA), professional soccer isn’t a...

Sapiens Summary Chapter 13: Success and Alternate Paths of History

The creation of a global society was probably inevitable, but not the type of global society. For instance, the language of our global society is English. Why is English so prevalent and not, say, Danish? Why are we a society dominated by monotheistic religions and not dualistic ones?

We don’t know the answers to these questions, but there are two things we can say about history: 1) It isn’t predictable and 2) Its progress doesn’t necessarily benefit humans.

History Isn’t Predictable

The hindsight fallacy (or hindsight bias) is the human tendency to believe that events that have already happened were more predictable than they actually were. Looking back, we think we could have predicted how history would unfold—it seems obvious in hindsight. But while today we can describe how history has unfolded so far, we can’t say why it’s turned out the way it has.

For example, we can detail the events leading up to Christianity’s take-over of the Roman Empire, but we can’t determine the causal links between these events. We don’t know why Emperor Constantine chose to convert to Christianity when he could have continued to practice his own polytheistic religion....

Sapiens Summary Part IV: Revolution of Science | Chapter 14: Knowing We Don’t Know

In the last 500 years, we’ve seen unprecedented scientific and technological growth, so much so that a time traveler from 1500 would recognize very little of our world. For instance, since 1500, the world population has grown from 500 million Sapiens to 7 billion. Every word and number in every book in every medieval library could be easily stored on a modern computer. Further, we’ve built skyscrapers, circumnavigated the earth, and landed on the moon. We’ve discovered the world of bacteria, can now cure most diseases caused by it, and even engineer bacteria for use in medicines.

All of these advances were made possible by the Scientific Revolution.

Changes in the Way We Understand the World

In many ways, the Scientific Revolution was the result of a shift in the way Sapiens viewed the world and its future. We post-Scientific Revolution Sapiens understand the world differently than our ancestors:

1. We are willing to acknowledge our ignorance: Today, we assume there are gaps in our knowledge, and we even question what we think we know. As we’ll see below, this wasn’t the norm before the Scientific Revolution.

2. We emphasize observation and mathematics:...

Sapiens Summary Chapter 15: The Quest for Knowledge...and Land

As we know, those in power rarely seek knowledge for knowledge’s sake. As Europeans set out to conquer the world in the 18th century, imperialism and the Scientific Revolution became not only inseparable but indistinguishable. Expeditions had the dual purpose of colonizing new territories and making scientific discoveries, and each goal aided the other.

Before we explore how science and empire tied the knot, we need to ask a crucial question: Why were the Europeans the ones who took over the world?

European Dominance

Cortes only had 550 men. Yet he managed to conquer an empire of millions, the Aztecs. Similarly, England was a tiny, inconsequential island in the 18th century, yet Captain Cook’s arrival in Tasmania led to the near-extermination of Tasmania’s native population, who were hunted and driven off the land by the new settlers. Although it seems almost inevitable in hindsight, it wasn’t obvious that England would defeat Tasmania. How did Europe, such a tiny part of the world, come to dominate it? Prior to Cook’s expeditions, Britain and western Europe were negligible influences on the world stage.

Asia was the more likely world power. The Ottoman Empire,...

Sapiens Summary Chapter 16: The Myth of Capitalism

Science, in both its discoveries and the mindset it fostered, was one of the two greatest aids to imperialism. Capitalism was the other.

The Idea of Growth

To understand our modern economy, you really only need to know one thing: it’s growing.

This seems obvious to us, but for most of history, the economy remained static. Growth is a relatively recent phenomenon, and its incline has been steep: In 1500, global production was about $250 billion. Today, it’s around $60 trillion.

The Banker, the Baker, and the Contractor

To understand this enormous growth, let’s look at a hypothetical example:

Mr. Greedy is a banker. Mr. Stone, a contractor, finishes a job and puts his payment, $1 million, in Mr. Greedy’s bank. Now the bank has $1 million in capital.

Meanwhile, Mrs. McDoughnut wants to start a bakery in town, but she doesn’t have the money to buy a property for her business or buy the tools needed for her business. So she goes to Mr. Greedy at the bank to get a loan. Mr. Greedy loans her $1 million.

Mrs. McDoughnut needs a contractor to build her bakery, so she hires Mr. Stone for $1 million. She pays him and Mr. Stone puts this money into his...

Sapiens Summary Chapter 17: Revolution of Industry

Economic growth requires more than just trust in the future and the willingness of employers to reinvest their capital. It needs resources, the energy and raw materials that go into production. While the economy can grow, our resources remain finite.

At least, that’s what we’ve thought for centuries. But the energy and raw materials that are accessible to us today have increased as a result of the Industrial Revolution. We now have both better ways of exploiting our resources and resources that didn’t exist in the worlds of our ancestors.

For instance, for over 300 years, humans built increasingly more advanced vehicles, from carts and wagons to trains, cars, jets, and spaceships. In 1700, the vehicle industry relied almost entirely on wood and iron, so its resources were limited. But since 1700, humans have invented or discovered new materials such as plastic, rubber, aluminum, and titanium. We also have new energy sources. The industry relied on muscle power in 1700, but today factories use petroleum combustion engines and nuclear power stations to manufacture their vehicles.

As long as science keeps making discoveries, our resources are, if not infinite, at least...

Sapiens Summary Chapter 18: Revolution of Society

The Industrial Revolution caused many upheavals to society, including urbanization, the rise in power of the common person, the decline of patriarchy, and democratization. But the two biggest upheavals to society were artificial time and the replacement of family and community with state and market.

Major Change #1: Artificial Time

The Industrial Revolution brought the industrialization of time, our turn away from natural time to mechanized time.

Agricultural v. Industrial Time

Most societies in history couldn’t make accurate measurements of time, and it didn’t really matter. Time was dictated by the day and the seasons. This was “agricultural time.” The sun told you when to wake up and go to work and when to go home and go to sleep, and it also told you when to harvest your crops and when to plant new ones. You didn’t need a more accurate measure of time than where the sun was in the sky.

But with the rise of the Industrial Revolution, precise time started to matter. Let’s see why: if you’re a shoemaker in medieval times, you make every part of the shoe, from the sole to the buckle. If another shoemaker shows up late for work, it doesn’t affect you. But if you...

Sapiens Summary Chapter 19: Theories of Happiness

The Agricultural, Cognitive, and Industrial Revolutions have merged nations, creating a global empire. Further, these revolutions have grown our economy, giving us “superhuman” powers. Have these revolutions increased our happiness, as well? If they haven’t, what was the point? Can we call ourselves successful if we’re not happier today than we were yesterday?

Many researchers have used “subjective well-being” as a stand-in for happiness. This implies that happiness is a feeling, either one of pleasure in the moment or one of contentment in the long term. This theory depends on the assumption that we can judge people’s happiness by asking them how they feel. Although we can’t ask our ancestors how they felt, we can take current findings and apply them retroactively. To determine the progress of happiness, we’ll look at four theories of happiness: the “expectations” theory of happiness, the biological theory of happiness, the “finding meaning” theory of happiness, and the “present moment” theory of happiness.

The “Expectations” Theory of Happiness

**The most significant finding in the study of happiness is that long-term happiness is based on the gap between our...

Sapiens Summary Chapter 20: The Birth of a New Species

So far, we’ve discussed the history of Homo sapiens. But what about its future?

The future of our species may be relatively short, not because we cause ourselves to go extinct, but because we become an entirely new species.

For almost 4 billion years, species have evolved according to the principles of natural selection. For example, proto-giraffes who had longer necks than their contemporaries could reach higher branches and access more food. Therefore, they had a better chance of survival and passing on their genes. According to science, this wasn’t the product of intelligent design. It was the product of surviving animals passing on the characteristics that led to their survival.

For the last 4 billion years, species, including Sapiens, have been constrained by these laws of natural selection, but today, we’re on the brink of replacing natural selection with intelligent design.

With the Agricultural Revolution came a huge leap forward in the move from natural selection to intelligent design. This is when Sapiens started mating animals. Rather than merely wishing for slow, fat chickens, a sapiens could mate a fat hen with a slow cock to produce, fat, slow offspring....

Shortform Exercise: Reflect on Sapiens

Sapiens is full of counterintuitive ideas and new ways to view our history. Which ones impacted you the most?

What are your key takeaways from the book? In what ways do you see the world differently now than before reading the summary?