Wired for Culture: Origins of the Human Social Mind Read online

  ALSO BY MARK PAGEL

  Evolutionary Genomics and Proteomics

  with Andrew Pomiankowski (Sinauer, 2008)

  The Oxford Encyclopedia of Evolution

  (Oxford University Press, 2002)

  The Comparative Method in Evolutionary Biology

  with Paul H. Harvey (Oxford University Press, 1991)

  WIRED FOR

  CULTURE

  Origins of the

  Human Social Mind

  Mark Pagel

  W. W. Norton & Company • NEW YORK LONDON

  Contents

  Preface

  INTRODUCTION: The Gamble

  PART I • Mind Control, Protection, and Prosperity

  Prologue

  CHAPTER 1: The Occupation of the World

  CHAPTER 2: Ultra-sociality and the Cultural Survival Vehicle

  CHAPTER 3: The Domestication of Our Talents

  CHAPTER 4: Religion and Other Cultural “Enhancers”

  PART II • Cooperation and our Cultural Nature

  Prologue

  CHAPTER 5: Reciprocity and the Shadow of the Future

  CHAPTER 6: Green Beards and the Reputation Marketplace

  CHAPTER 7: Hostile Forces

  PART III • The Theatre of the Mind

  Prologue

  CHAPTER 8: Human Language—The Voice of Our Genes

  CHAPTER 9: Deception, Consciousness, and Truth

  PART IV • The Many and the Few

  Prologue

  CHAPTER 10: Termite Mounds and the Exploitation of Our Social Instincts

  References

  Bibliography

  Index

  Preface

  I BEGAN THINKING about the ideas that would lead to this book in the early 1990s while in a remote and barren region of Northern Kenya known as the Chalbi Desert. The Chalbi lies north of the town of Marsabit and to the east of Lake Turkana. Marsabit is about a day’s drive north from the town of Isiolo, which sits on the border of a region still called the Northern Frontier District, and that forms roughly half of Kenya. The Chalbi Desert is to some archaeologists the cradle of humanity, the place where the evolving lineage that would eventually lead to modern humans arose. It is a hot and arid region, short of water during the dry season, making it too dry for agriculture, but suited to nomadic pastoralists—people who live by herding animals.

  In the Chalbi Desert most pastoralists herd sheep, goats, and camels. A pastoralist’s animals are an edible bank account, with varying interest and risk rates. The sheep reproduce quickly but are finicky about what they eat. Goats will eat anything but reproduce less quickly. Camels are the gold bullion of pastoralism: they can survive the harshest conditions but are very slow about making more camels. For the nomadic pastoralists, life is like being an itinerant investment manager. Every day begins with the question of how best to divide one’s resources and efforts among their four-legged investment policies: how many sheep should I have, and when I get that number should I trade them for goats and camels?

  The Gabbra are a tribe of nomadic pastoralists who live in the Chalbi and descend from Cushitic people who trace their origins to the Horn of Africa. One of these Gabbra, a man called Dido, had seldom been more than about thirty miles from his birthplace, and had spent his life herding his animals and owning what he could fit on the back of a camel when it came time to shift from one area of pasture to another, something these nomads might do several times per year. In addition to his native Gabbra language, Dido could speak English from spending time among missionaries. But Dido also spoke four more languages: Rendille, Samburu, Turkana, and Swahili. I wasn’t surprised about Swahili because it is a trade language spoken all over East Africa. But Rendille, Samburu, and Turkana are the languages of other nomadic pastoralists who also live near the Chalbi Desert and who make their living in the same way as the Gabbra. I asked him why he could speak their languages and he replied: “So I can talk to them.”

  I was asking a different question. What I really wanted to know was why there were four different tribes of nomadic pastoralists all living in the same area and herding the same kinds of animals, whose genetic differences were negligible, and yet who had divided up the land and their lives so exclusively as to speak different languages. Why were there four tribes with different languages, customs, habits, and traditions, and not just one? Why do we humans have a tendency to form into small tribal groups rather than living as one large and homogeneous society? This is a worldwide phenomenon, not confined to this desert region of Northern Kenya. There are currently as many as 7,000 different languages spoken, or 7,000 mutually unintelligible systems of communication in one species, marking out at least 7,000 distinct societies. This is more different systems of communication in a single mammal species—for that is what we are—than there are mammal species. It is 7,000 different ways of saying, “Good morning,” or, “Looks like rain today,” and means that humans uniquely and strangely among animals often cannot communicate with other members of their own species.

  For many anthropologists, culture in its wider manifestations—including rituals, belief systems, religion, and customs—simply exists and develops its own momentum and directions in separate groups. For them, our cultural diversity arises as a consequence of geography. The wider our species spread after leaving Africa probably sometime between 60,000 to 70,000 years ago, the more different societies and languages would eventually emerge. But this fails to explain a key fact of human societies: that there are many more than we would expect from simple territorial expansion of our species, hinting at more fundamental social and psychological causes. In fact, it is where people are found most closely packed together—the least geographically isolated—that we find the greatest diversity of cultures. There are regions of the northeast corner of coastal Papua New Guinea where a different language is spoken every few miles. I once met a Papuan man from that area and asked him if this could be true. He replied, “Oh no, they are far closer together than that.”

  This cannot be a simple consequence of geography, and if we are a species with a predilection to form into societies with separate and distinct identities, then this is something that we are going to have to come to grips with in a modern world. It is also something that we will want to understand because it clashes with another feature of our species. The evolutionary biologist Robert Trivers began something of a revolution in our thinking about humans when in 1971 he put forward his idea of “reciprocal altruism.” It showed a way that two individuals who were not related to each other could nevertheless benefit from mutual acts of altruism. Here was a way that natural selection could escape Tennyson’s “Nature, red in tooth and claw” and promote cooperation among people who in evolutionary terms were, by instinct and temperament, competitors. By the early 1990s evolutionary biologists and anthropologists were coming to appreciate that human beings had taken this even further, having developed the means to behave altruistically toward others and even do so without any expectation of a return from those others. We are capable of great acts of charity, helping others in distress, and of simply being kind, generous, and friendly. No other animal does such things, and so it is a capability we have evolved only relatively recently. But why? So here are two observations that need to be put together—our unmatched ability to get along with each other set against our tendencies to form competing societies often not far from conflict.

  Evolutionary biologists are accustomed to recognizing that some kinds of patterns in the distribution of animals and plants and how they live reveal clues about those species’ tactics in surviving. It is then a matter of working backward from the patter
ns to discover what kinds of survival strategies would give rise to them. With humans, we want to ask what is the nature of culture as a survival strategy that it would have this feature of forming us into so many small societies, which seem to act in some respects like an extension of our bodies. We are devoted to them sometimes to the point of self-sacrifice, we cooperate with others inside of them, and we use them to advance our interests. At a psychological level, we display forms of social behavior conducive to living in small groups, such as rewarding cooperation, punishing those who deviate from norms, being wary of outsiders. What kinds of explanation can we give for these features of our lives?

  This book is an attempt to answer some of these questions. I am grateful to the following people (in no particular order) who one way or another have given me information, suggestions, and ideas that have been helpful in writing it, some of them so long ago that they won’t remember and will be surprised to see their names here: Andrew Meade, Chris Venditti, Andreea Calude, Russell Gray, Rutger Vos, Paul Harvey, Tecumseh Fitch, Irv DeVore, Kevin Laland, Richard Sibly, Ruth Mace, Quentin Atkinson, Jon Wilkins, Mark Beaumont, David Krakauer, Jessica Flack, Matt Ridley, Colin Renfrew, Karl Sigmund, Robert Trivers, and Preethi Chandramohan. I am also grateful to the University of Reading and the Santa Fe Institute for providing me the time and space to think and write. The Leverhulme Trust has supported some of my work on language evolution that I report in a later chapter. My children Thomas and William remind me that life is both simpler and yet more unpredictable than I ever imagined, and therefore worth explaining.

  My agents Katinka Matson and John Brockman provided particularly valuable advice and suggestions, and put opportunities my way. Laura Romain and Ann Adelman respectively shepherded and copyedited the manuscript as it moved from typescript to book. And I owe a special degree of thanks to my editor Angela von der Lippe. She carefully read the entire manuscript, making many useful suggestions that improved it greatly.

  INTRODUCTION

  The Gamble

  That human nature is defined by our response to culture

  THE ENGLISH 4TH Baron Raglan, Major FitzRoy Richard Somerset of the Queen’s Grenadier Guards, once remarked that “culture is roughly everything we do and monkeys don’t.” This comment nicely summarizes one of the main messages of this book. Human beings have not always been as we know us now—sentient, big-brained, naked, prolix, artistic, wary, scheming, generous, warlike, forgiving, vengeful, religious, and moralistic. Instead, we were launched as recently as 80,000 years ago when our genes undertook a remarkable gamble. Around that time a species of upright apes, close evolutionary relatives to the chimpanzees, began to perfect a new way of life. Nothing in this species’ predecessors would have hinted at what was about to emerge, or that it would have such startling effects. Where previously they had roamed the African savannah for at least a million years, hunting and foraging in small family groups, the new species now came to live in larger tribal societies in which people worked together, customs and systems of beliefs arose, ideas, skills, and technologies were shared, languages evolved, and dance, music, and art appeared. Within a few tens of thousands of years, these tribal groups would spread out to occupy the world as some of them developed the means to live near the sea, others the ability to survive the desert or to inhabit jungles, forests, mountains, or plains. In what was little more than an instant in our long evolutionary history, we had become a single species with a global reach and ways of life as varied as collections of different biological species, and we were soon to become the sole survivor of an evolutionary lineage that had spawned at least six previous human branches.

  The world was witnessing the final stages of a shift in the balance of power between our genes and our minds. Human beings had discovered culture. It was not high art and symphonies—those would come—but knowledge, beliefs, and practices acquired from watching, imitating, and learning from others. Today, we take our possession of culture for granted, but it was a development that had to await nearly the entire history of life on Earth. Our world is four and a half thousand million (4.5 billion) years old, and might have been a harsh, rocky place devoid of life for its first 700 million to 1 billion years. Then, from fossil traces buried deep in ancient rocks, we know that life sparked into existence and for the next 3.5 billion years genes ruled, transmitting the instructions that organisms used to survive and reproduce. For most of that time, life consisted of simple one-celled organisms, direct ancestors of today’s bacteria; but these gave way around 1 billion years ago to the first multicellular organisms, simple creatures like today’s sponges. Five hundred million years after that the first animals with arms and legs would rise up out of the sea and walk on land. These land animals would in turn evolve for yet another 500 million years before the evolutionary lineage that we call the hominins came on the scene, a mere 7 million years ago.

  Even then, it was only when our species arose within this hominin lineage just 160,000–200,000 years ago that a competitor to the rule of genes finally appeared. Our invention of culture around that time created an entirely new sphere of evolving entities. Humans had acquired the ability to learn from others, and to copy, imitate and improve upon their actions. This meant that elements of culture themselves—ideas, languages, beliefs, songs, art, technologies—could act like genes, capable of being transmitted to others and reproduced. But unlike genes, these elements of culture could jump directly from one mind to another, shortcutting the normal genetic routes of transmission. And so our cultures came to define a second great system of inheritance, able to transmit knowledge down the generations. For humans, then, a shared culture granted its members access to a vast store of information, technologies, wisdom, and good luck. The only other example like this in nature is the lowly bacteria. These simple one-celled organisms cannot exchange ideas, but they have acquired a variety of means for exchanging genes among individuals and even among different species, granting them access to a vast store of genetic technology. And, like us, they have shown great inventiveness and versatility, occupying nearly every environment on Earth.

  Our cultural inheritance is something we take for granted today, but its invention forever altered the course of evolution and our world. This is because knowledge could accumulate as good ideas were retained, combined, and improved upon, and others were discarded. And, being able to jump from mind to mind granted the elements of culture a pace of change that stood in relation to our genetical evolution something like an animal’s behavior does to the more leisurely movement of a plant. Where you are stuck from birth with a sample of the genes that made your parents, you can sample throughout your life from a sea of evolving ideas. Not surprisingly, then, our cultures quickly came to take over the running of our day-to-day affairs as they outstripped our genes in providing solutions to the problems of our existence. Having culture means we are the only species that acquires the rules of its daily living from the accumulated knowledge of our ancestors rather than from the genes they pass to us. Our cultures and not our genes supply the solutions we use to survive and prosper in the society of our birth; they provide the instructions for what we eat, how we live, the gods we believe in, the tools we make and use, the language we speak, the people we cooperate with and marry, and whom we might fight or even kill in a war.

  Most of us assume without reflection that it has always been this way, that human beings have always occupied the world, and that somehow we are the natural and rightful rulers of its domains. But we are new on the scene, and even newer around the world, having only ventured permanently out of Africa probably sometime in the last 60,000 to 70,000 years. Even as recently as 80,000 years ago, our species’ continued existence still hung in the balance. An extraordinary degree of similarity in the genes of people from all over the world tells us that we all share a recent common ancestry. In fact, genetic studies now reveal that our ancestors might have dwindled to as few as 10,000 individuals—some say even fewer—making humans as endangered 80,000
years ago as a rhinoceros is today. Then our numbers began to grow and human culture began to flourish, and our species, having come perilously close to extinction, reached a point of no return. Our minds were now firmly in executive control of our fates, and we were showing the adaptability, and producing the artifacts and culture that would propel us out of Africa, and then around the world—specialized stone tools and spear points, carved fishhooks, clothes, shaped blades and instruments, but also sculpted figures, ceremonial burials, musical instruments, and cave art.

  The world is now a remarkably different place from what it was throughout the first 99.996 percent of its history. Almost everything around you in your bustling everyday lives is owed to the new evolutionary world in which ideas could accumulate on top of ideas, and most of those ideas were first thought up by someone distant to you in time and space. Having culture is why we watch 3D television and build soaring cathedrals while our close genetic relatives the chimpanzees sit in the forest as they have for millions of years cracking the same old nuts with the same old stones. Even so, having become the first species to throw off the yoke of its genes, our life in the presence of culture would usher in an irony. It is that we have fallen in thrall to the new sets of instructions our cultures provide. This is because to take advantage of culture meant evolving a new kind of mind. It had to be a cultural blank slate or tabula rasa, a compliant or docile mind, designed to be programmed by and embrace the culture into which it happened to be born. A wolf brought up by sheep will remain a wolf and soon turn on its benefactors, but a newborn human must be ready to join any cultural group on Earth, and without knowing which. It might find itself living on the Arctic ice, the Russian steppes, or sailing across Polynesia; it might find itself in the Australian Outback, the deserts of Arabia, on the prairies of North America, or the African savannah, on an island in the Indian Ocean, or fishing along the rich tropical coasts of Papua New Guinea. And so we have had no choice but to evolve to allow our culture to occupy our minds, writing its language and story into our consciousness.