#2 - Sapiens by Yuval Harari

Sapiens - A Brief History of Humankind, by Yuval Noah Harari, is a fascinating and ambitious book that attempts to tell the story of humanity, compressing 2.5 million years into 466 pages. In order to achieve such feat, it focuses on 3 major events: the Cognitive Revolution, the Agricultural Revolution and the Scientific Revolution. It is based on scientific evidence, but also includes lots of theories from scientists and historians, as well as opinions from the author. Sapiens is undoubtedly one of the best books I have ever read, due as much to its content as to the brilliance of Yuval's writing. It's been a great conversation-starter and thought-provoker, changing my perspective on life in several ways.

Part 1: The Origin of Homo Sapiens: the Cognitive Revolution

We humans like to think of ourselves as special. We don't like to be called animals. In fact, I was once doing a presentation at an academic english class, and I said something like "as animals, we humans need to move....". The professor was quick to correct me: "Mauro, we don't typically refer to humans as animals! It's strange, and you shouldn't do that". A central argument of Part 1 is that, yes, we are indeed just animals. For most of our existence, which is about 2.5 million years, we had no more influence on earth than a lion or a koala.

We are part of the Great Apes family, which includes chimpanzees, gorillas, and other apes. Yuval calls them our cousins. Looking more closely, we also used to have siblings: other human species. Homo Erectus, Neanderthals, Homo Sapiens, Homo Floresiensis, Homo Rudolfensis, etc.. You probably remember some of these from history classes all the way back to primary school, like I did. But what I didn't know was that, for most of the 2.5m years of human existence, several of these species lived at the very same time, in different parts of the world. And some of them even met. Since about 10,000 years ago, only one species exists: Homo Sapiens (henceforth simply referred to as Sapiens). We're all Sapiens. All other species are now extint. If this sounds strange, consider that there are several species of dogs or bears coexisting today.

Sapiens was cognitively superior than all other human species. Sapiens evolved in East Africa, and migrated to Eurasia around 70,000 years ago, where they found the Neanderthals, which at the time inhabited Eurasia. What happened when they met? One theory, the Interbreeding Theory, states that Sapiens mated with the other species, forming present-us. According to this theory, present-day human is a mixture of Sapiens and other human species such as Neanderthals. An opposing theory is the Replacement Theory, which defends that Sapiens didn't mate with the other human species. Instead, the other species either died out, or were killed off by Sapiens. So present-day humanity is pure Sapiens. The validity of each theory has major consequences, because if the Interbreeding Theory is true, than all the social conflicts driven by human differences would be amplified: If horrible things such as apartheid were based on minor differences such as skin color, what would have happened had we discovered major genetic differences between us?

Sapiens was cognitively superior, but why? What set us apart from the other human species, as well as all other animals? One major physiological feature that distinguish us from other animals is our massive brain. Why did our brains evolve to be so large? Scientists don't know. Interestingly, Neanderthals had an even bigger brain than Sapiens. So why did they lose out to Sapiens? Yuval tells us that something in the human brain structure changed with Sapiens, which allowed our superior intelligence to take place. Scientists don't know what that was either. Nevertheless, this change allowed the development of superior linguistic capabilities. Sapiens were able to communicate with each other much better than any other animal. In fact, this is the central outcome of the Cognitive Revolution: better language skills meant better collaboration, which meant other species couldn't stand a chance against Sapiens.

With advanced linguistic skills, Sapiens could:

• describe places and things in the world with much more detail and expressiveness. This is useful for example for sharing precise information about food whereabouts, and for better planning of hunting journeys;
• describe other humans well, as in: gossip about others. Gossip allows Sapiens to know each other very well, which in turn enables much more effective social collaboration. In fact, some researchers believe that this was, and still is, the bulk of human communication (think celebrity or co-worker gossip);
• think and talk about things that don't exist, which is a skill unique to Sapiens. Although animals such as monkeys can tell each other about food or danger, as far as scientists can tell, no other animal on earth can think about things that do not exist; Sapiens can think about fictive concepts such as gods, justice, nations, limited liability companies, and so on.

Sapiens, a social animal, evolved to live within small groups of people, called bands. Individuals knew each other very well within these groups. So Sapiens evolved to collaborate with members of the band by means of strong personal relationships. This creates a serious limitation: humans have a hard time trusting and collaborating with strangers. When the group is small enough, it's easy to maintain one-to-one intimate relationships between members. However, when the group size crosses a tipping point, shown to be around 150 individuals, it's impossible to know everyone on an intimate level. So it becomes impossible to know who to trust, who to fear, who is a good worker, who is sleeping with whom, who hates who, and so on. As a consequence, the social order of such groups collapses, and smaller groups are formed, often competing for resources afterwards. So how is it possible that in present day, humans live orderly among millions of other humans in cities like New York or New Delhi, while interacting with dozens of strangers on a daily basis? That is mostly due to our ability to believe in things that don't exist, i.e. fiction or myths. Myths are concepts such as religion, the law, nations, human rights, and so on. These are concepts that are not to be found in nature, but rather exist in our collective imagination. They allow us to organize ourselves effectively in large numbers, guiding our behavior and creating social order. When you meet a stranger, you can mostly trust that they won't try to kill you, because you both believe in the myth of law. This was a mind-blowing insight I got from the book.

In short, the ability to believe in myths allows us to create social orders, which in turn allow us to coexist and cooperate by the millions. But why did we evolve to be social in the first place? The answer is that it's hard for a human being to survive on their own. Humans evolved to walk upright, which narrowed women's hips and contracted their birth canals. Concurrently, humans evolved to have large brains and heads, thus making it risky to give birth. In consequence, natural selection favored early births, as giving birth to a smaller baby decreased the odds of labor deaths. The result is: a human baby is basically useless when it's born, requiring years of nurture to become independent (this is in contrast to animals like cats, which become independent after a few short weeks). A single mother cannot raise their child while also foraging for food and protecting themselves from predators. Therefore, the humans that tended to survive and multiply where those that managed to form strong bonds with each other, giving birth to our social tendencies. Our innate drive to be social is a very interesting topic for me. It probably explains so much of our world and behaviour. In the next few weeks, I'll be exploring this topic by reading books such as Social Leap. Subscribe to the newsletter if you haven't, so you can get in-depth, thoughtful pieces such as this on a (hopefully) weekly basis.

Besides enabling millions of humans to cooperate, Sapiens' ability to believe in myths also means that the way we behave can change rapidly. The behavior of most animals is largely explained by their biology. Honeybee societies are biologically programmed to be composed of worker, drone and queen bees. Changes in behavior require changes in their DNA, which take hundreds of thousands of years to manifest. In contrast, human societies can rapidly change their social order, by simply replacing the myths they believe in. A country can go from communism to a democracy in a matter of weeks (e.g. in political revolutions); a person can go from behaving according to the Catholic church to behaving according to the Islamic faith, and so on. Let's pause for a second and appreciate how amazing this is. Humans (partially) bypassed biology and evolution. We can behave in ways that go against our biological urges, such as when priests willingly forego sex and reproduction, which are strong biological imperatives. Passing new behaviours to future generations does not require genetic mutation, but simply requires passing on stories. This means our societies evolve very rapidly, whereas most other animals, including archaic human species, behave in largely the same way for millions of years. This insight made me even more aware of just how powerful storytelling is. The collection of myths or stories a society believes in is called culture, and the evolution of culture across time and places is what we call history. In order to understand human behaviour and motivation, which I am very interested in, we must study both biology (e.g. genes, neuroscience, cognition) and culture (e.g. ideas, values, history).

Ok, those are the most important aspects of the Cognitive Revolution. It's important to mention that, as you could probably tell, scientists don't have strong answers to a lot of important questions. Our current understanding is somewhat limited, due in part to the challenge of making sense of a world that existed several thousand years ago based mostly on fossilized remains. Moreover, this book compresses millions of years into 466 pages, which comes with the tradeoff of excluding tons of details. Therefore, take these narratives with a grain of salt, and be prepared to update your understanding as new evidence inevitably emerges in the future, or when you dive deeper into specific subjects.

Part 2: From foragers to farmers: the Agricultural Revolution

For most of our history, up until about 12,000 years ago, humans were foragers: hunters and gatherers that lived in forests, savannas and even in the arctics. Small groups of humans, called bands, went out daily in search of food. Humans had a varied, opportunistic diet that consisted of picked fruits, plants, roots, nuts and insects, as well as some small sized game and scavenged remains. While foraging, they observed and learned incessantly about their environment, such as where certain animals resided, the growth patterns of plants, weather patterns, or which foods made you sick. They were always surrounded by their band members to whom they held strong personal relationships. Ancient foragers had a life expectancy of about 60 years, and were largely free from infectious diseases, which Yuval argues came mainly from domesticated animals. The human body became very well adapted to these living conditions, since we lived like this for hundreds of thousands of years. In short, Yuval paints a picture of an average ancient forager who was very fit, healthy, mobile, cognitively engaged, emotionally fulfilled, and who lived an adventurous, exciting life.

In present day, life is completely different. We live in post-industrial-era megacities made of concrete. We are largely sedentary, spending countless hours in office chairs, inside cars, or watching TV. Many of us have poor diets, consisting of lots of junk food and sugar. Modern environments, technology and social expectations push us to have poor sleeping habits. Hundreds of millions of people work long hours in unfulfilling jobs in which they do the exact same mindless task every single day (e.g. factory workers). Millions of people move away from their families in order to study or work, resulting in feelings of loneliness. In short, our lifestyle changed drastically, leaving virtually no time for evolution to do it's thing. This is a very important insight: our bodies and brains (cognition, psychology, emotions, etc.) evolved for the life of a forager, which is wildly different from the life of a modern-day office worker. This can be problematic. The instincts that garanteed our survival in the past (e.g. binge-eating fruits because they were calorie-dense rarities), can be harmful in today's affluent societies (e.g. not being able to resist binge-eating a bag of Oreos). On the one hand, bypassing evolution helped us master the world. On the other hand, it's causing us major health and wellbeing problems. Nevertheless, our bodies are still evolving. For instance, we developed a tolerance to dairy only about 7,000 years ago (source), and our forager ancestors have been able to thrive in all kinds of natural habitats with widely different available resources. So there is a more nuanced approach then the one offered in the book.    

The above details are about as certain as we can be about the lives of our forager ancestors who lived between the Cognitive Revolution (~70,000 years ago) and the Agricultural Revolution (~12,000 years ago). Not much evidence survived past their time, since these societies had almost no possessions, built everything in wood (except for a handful of stone tools) and did not write (except for a handful of hard-to-decrypt cave paintings). The research methods available today rely heavily on fossilized remains, which cannot give much insight into their cultures, social orders, moral values, religious beliefs, artistic prowess, and so on. Were they peaceful? Were there wars and revolutions? Philosophers? Musicians? Kings? We just don't know.

At some point, starting from about 12,000 years ago up until about 5,000 years ago, humans from different parts of the world independently learned how to grow plants, and transitioned to being farmers. 90% of the calories we consume today come from the handful of plants domesticated during that period. Although many scholars believe that the Agricultural Revolution was a great leap for humanity, Yuval disagrees. For him, this revolution was a trap. Farmers became more susceptible to famine, since they relied on a handful of crops for nutrition, unlike foragers. If the harvest wasn't good, thousands or even millions of people starved to death. Getting most of your calories from wheat or rice meant that people were malnourished. People got infectious diseases that originated from domesticated animals, which foragers avoided since they only domesticated dogs. Ancient farmers worked long, hard hours doing tasks that strained their necks, backs and knees. In his opinion, the biggest winners were the crops, which basically domesticated us. From an evolutionary perspective, these crops and animals have been extremely successful enterprises that dominated the world by means of a symbiotic deal with humans. Uruguay, Argentina and Brazil have more cattle than humans. Nevertheless, agriculture turned people from nomads to sedentary, and was a key factor in population increase, which went from about 8 million 12,000 years ago to close to 8 billion today.  

Agriculture also gave birth to complex imagined social orders, since larger numbers of people needed a way to share resources such as land and harvests. These were based on myths (or stories), since humans lack a biological instict to cooperate with strangers (see Part 1). A few examples are the Code of Hammurabi, which allowed hundreds of thousands of Babylonians to cooperate, and the American Declaration of Independence, which today still serves as a cooperation manual for hundreds of millions of people. 'Cooperation' here may be too generous of a word, since these social orders often involved oppression. Usually, large parts of the population got the bad end of the deal, being classified as peasants or slaves, working hard to pay taxes to an elite few. It's easy to think about the Hammurabi Code as a (ridiculous) myth, but difficult to accept that modern concepts such as human rights, nations, constitutions, laws, right and wrong, gender roles, are also myths, with no basis in nature or biology. Human rights are not to be found in our genetic code or anywhere else in nature, yet they feel real. These myths shape our physical world, our way of thinking, our values and our desires. They exert a huge amount of power over us. They are often self-reinforcing. Every society has a set of imagined reality that guides people's behavior. Like Steve Jobs said:

" Everything around you that you call 'life' was made up by people who were no smarter than you. "

With more complex societies came the need to keep track of an increasing amount of information, such as how much taxes a specific peasant paid five years ago. Due to their lifestyle, human's forager brains evolved to remember huge amounts of botanical, zoological, topographical and social information, but not numbers. Thus writing was born, first with partial scripts used for accounting, and later with general purpose scripts. Mathematics eventually followed. Today, the 0-9 numeral script, invented by the Hindu and popularized by the Arabs is one of the most ubiquitous languages in the world.

Part 3: Human Kind becomes one

Yuval identifies a trend in human history post the Agricultural Revolution. Humanity is advancing from a state of isolation to a state of globalization. Independent cultures are converging to become one and only. Sapiens, a social animal that evolved to see the world as "us" (close family, tribe) and "them" (rest of the world) is now thinking about humanity as a whole. We're now facing challenges that transcend cultures and geographical boundaries. Human societies gradually invented systems to cope with the lack of an innate ability to trust strangers. These were based on fictive concepts. The 3 main systems that enabled the unification trend are: money, empires and religion. Money enabled a global economy. Empires and religion enabled global cultures.

Let's start with money. Ancient foragers were mainly organized in tribes who produced most things they needed internally. Tribe members shared food and services by means of favors, because everyone knew everyone. With the rise of villages, cities, and better transportation links, people began to work full-time on specific skills. This development brought the need for large numbers of strangers to trade. Personal relationships and favors were no longer an option. So people started bartering: trading one good or service with another. Bartering proved to be challenging for 2 main reasons:

• Villager João had to trade what they produced (e.g. carrots) with what Maria produced (e.g. massages). What if Jõao really needs a massage, but Maria really doesn't like carrots?
• It was hard to estimate the value of goods and services. How many carrots is one hour of massage worth? How are you going to remember the value of pairings of thousands of goods and services, across time and changing circumstances?

These challenges were solved with the invention of different forms of money, such as grain, shells, silver, coins and more recently, banknotes and electronic 0s and 1s. Money solves the first problem above because traders need not find others who are interested in what they sell: everyone always wants money, because everyone else is willing to accept it too. It also solves the second challenge, because traders only need to remember the value of the products that they make.

But what is money? It is nothing more than the product of our collective imagination. If everyone believes in its value, then it is valuable. If people suddenly stop believing in it (e.g. in financial crises), then it loses its value and stops working. Throughout history, people believed in different forms of money based on guarantees from elites such as kings, who ensured it would not be forged (often through violent punishment). Nowadays, people believe in the guarantee of states (e.g. the American government) or in the accuracy of decentralized computer systems (e.g. bitcoin). Money serves 3 main purposes: unit of account (how much is X worth), transportation of value across time and space, and means of exchange. The invention and development of money enabled increasingly larger groups of people to trade effectively. Today, we have a global economy powered by internationally trusted currencies such as the euro.

Secondly, we have empires. Empires are political orders with a huge desire to conquer other lands. They believed other people would benefit from being conquered, as the empire elite believed to possess a superior lifestyle that the conquered people would be thankful to have the opportunity to adopt. So the empire would go to a foreign land, conquer its people, force them to adopt their culture, and sometimes also adopt certain aspects of the culture of the conquered. An empire would rise, conquer, then collapse. A new empire would take its place, and this same story would play out over thousands of years. The result is that we now have a world in which the same lands have been governed by several different empires throughout history, influencing cultural aspects such as ethnicity, language, architecture, gastronomy, etc. So you can't tell for sure what is Italin, what is American or what is Mozambican culture. A lot of Italian food only became Italian a few hundred years ago (e.g. tomatoes are not native to Italy). It's hard to separate, to say what is original and what isn't. Nevertheless, the quest to conquer other lands meant more and more people lived under the same social order, believing in the same myths.

Finally, we have religion. Religions are "systems of human laws that are founded on the belief in superhuman laws", with the aim to guide human behavior. Yuval tells us that religion is likely to have started from our foraging ancestors, who likely practiced animism. Animism is a belief in the supernatural powers of animals and trees around us, accompanied with the belief that humans are just another animal among others. From there, we transitioned to a belief in multiple gods, called multi-theism, which increasingly saw the world as a product of the relationship between men and gods. Finally, we transitioned to a belief in a single god, such as in Christianity or Islam, although some elements of multi-theism are still present in these religions (e.g. concept of saints, or God and Devil in Christianity). How did Christianity or Islam become so popular? Most religions throughout history were very local, with no interest in expansion. In contrast, today's most popular religions had a fervent belief that their way of living is the only right way, and thus  considered it a mission to convert everyone everywhere. As a result, there are now 2 billion Christians, 1.5 billion Muslims, 900 million Hindus, etc.

Of course, there are hundreds of millions of secular people as well. It seems to me that more and more people are abdicating religion, specially when confronted with the logical contradictions that can arise. Yuval argues that religion is alive and well. Instead, we're moving away from a belief in the supernatural: gods, ghosts, etc., to a superhuman belief in man, as in, Homo Sapiens. Yuval considers communism, nazism, capitalism, humanism, etc to be religions, because they are founded on superhuman beliefs in human worth and divinity. The belief that Homo Sapiens, one animal out of millions on earth, is at the center of everything. On the one hand, that sounds ridiculous and self-centered of us. On the other hand, isn't it normal that an animal sees things from the perspective of itself?

Part 4: Homo Sapiens masters the world: the Scientific Revolution

Throughout most of human history, all cultures believed that the answers to the most important questions were already known. Societies believed that all answers could be found on religious texts, or from the wisdom of the elderly. Consequently, very little progress was seen in terms of knowledge and technology. That changed about 500 years ago, when Sapiens admitted its ignorance. People began assuming that they did in fact not know the answer to the most important questions. This mental revolution gave Sapiens the unprecedented ability to understand and rule the world. We've been able to improve the human condition by, for instance, greatly reducing world poverty and increasing life expectancy. In fact, Yuval argues that the main project of the Scientific Revolution is the defeat of death. Modern science is based on three directives: collect observations; use mathematical tools to express comprehensive theories; and use this knowledge to gain power. Science favors new observations versus old ones or conventional wisdom, constantly updating theories and increasing our understanding of the world. To me, it's mind-blowing how a simple change in mindset can result in so much progress. We've had the same cognitive abilities for 70,000 years, yet most of the knowledge and technology we take for granted today were produced during the last five centuries. This leads me to believe that the world is going to look very, very different in a short period of time, as the pace of technological advancement is astonishing. One hell of a time to be alive, isn't it?

Scientific thinking first flourished in Europe, as it was a fertile ground due to imperialism and capitalism. Post-1500 Imperialist Europe realized that with new geographical knowledge came new power. Therefore, they started including scientists in their expeditions, who would learn about the natural riches of the "discovered" territories. Until 1750, Europe was relatively insignificant in global politics, with Asia accounting for 80 percent of the world economy. By 1900, Europe dominated most of the world and its territory. Most other empires throughout history believed that they already understood the world, and expanded to acquire territories and spread their own visions. They drew maps that were complete, with unfamiliar areas left out. By contrast, European empires drew maps with empty spaces, which was an early sign of scientific thinking; an admission of their ignorance of large parts of the world. Europeans eventually arrived in America, and realized that they needed to study its geography, fauna, flora, climate, languages, cultures, etc. in order to be able to dominate it. They did the same in Africa and Asia, creating a network of bases around the world, an unprecedented feat at the time. Today, a lot of our world has been heavily influenced by Europe. Take the example of Mozambique, my home country. My native tongue, and Mozambique's official language, is Portuguese. Our education system is from Portugal. A lot of our gastronomy is from there. Many streets are named after Portuguese people. Our economic systems and government are modeled after theirs. I could go on and on.

Then we have capitalism. Capitalism was the other critical component that enabled science to develop in Europe. After all, scientific research needs to be funded. Prior to the modern era, people did not have much optimism towards the future. They believed that the best times were behind them. As a result, credit was hard to come by, which constrained new developments, which in turn constrained economic growth. People believed the economy to be a fixed pie, which meant that economic growth of one business or individual must come at the expense of others. The scientific revolution brought the idea of progress, the idea that life conditions would improve if resources were invested into research. This change of mindset made credit more accessible, which made profitable entrepreneurship endevours more viable. People then started investing in imperialist expeditions. When they realized that putting all of one's money in a single expedition was too risky, they created joint companies that distributed the risk among many investors. People then began buying and selling their stake in these companies. Soon, stock markets in cities such as Amsterdam and London were created, as dedicated marketplaces to exchange stakes in expedition companies. In short, capitalism indirectly funded early scientific endevours, by funding imperialist expeditions.      

Grande Finale: Can Homo Sapiens become God?

Yuval concludes the book with some thoughts on the future of our species. In fact, he wrote a whole new book on the subject, called Homo Deus, which I'll be reading at some point later this year. Due to the scientific revolution, Homo Sapiens has been able to acquire unprecedented knowledge of how our bodies work. Could we one day have people that can live forever? That seems crazy, but consider that besides the fields of disease cure and prevention, there are thousands of scientists focusing on understanding the mechanisms of aging, and how to stop it (search for 'longevity science'). Scientists today are able to synthesize simple organic tissue. Could we one day replace entire faulty organs? Could we one day become cyborgs, organic beings augmented by technology? Like Elon Musk argues, we are already cyborgs, as we already augment our intelectual capabilities such as memory with our phones, for instance. Could this relationship one day become tighter? How about uploading our consciousness into cumputers? Today we have very elementary versions of Artificial Intelligence, that is, computer programs that exhibit intelligent behavior, such as self-driving cars. What is in store for the next millennia?

These developments all seem far off into the future, not likely to materialize within our lifetimes. But even if it takes 5,000 years, isn't that a drop in the ocean compared to the millions of years that have taken us to get to where we are? In the next hundreds to thousands of years, we might have to deal with a human species that is so modified that it would not be Homo Sapiens anymore. An interesting question is what these developments will do to discussions about what it means to be human. It's also interesting to wonder how these changes will take place. Will these technologies be available to everyone, or restricted to an elite few? Are we even going to survive long enough, given global threats like climate change? Of course, nobody has answers at the moment, as history behaves more like a chaotic system, impossible to predict. In fact, today's world could have looked very different had a few things turned out differently in the past. I recommend anyone insterested in these topics to watch the very popular Netflix show called Black Mirror. You can email me recommendations too :).

That's it. Hope you learned a few things from this article. I encourage you to send me an email (hello@maurobanze.com) with your thoughts and feedback. It would be awesome to connect with people with similar interests. If you want more of these, please subscribe to the (hopefully) weekly newsletter using the form below. Topics I'm focusing on: human nature and behaviour; how to learn effectively and reason well; what makes us happy; and how to be healthy and perform at the highest level. I'll be writing thoughtful, long-form articles such as this.

Thank you for reading.