A Hunter-Gatherer's Guide to the 21st Century E-Book

Heather Heying

• Herausgeber: Swift Press
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 504

Veröffentlichungsjahr: 2021

Beschreibung

A bold, provocative exploration of the tension between our evolutionary history and our modern woes – and what we can do about it We are living through the most prosperous age in all of human history, yet we are listless, divided and miserable. Wealth and comfort are unparalleled, but our political landscape is unmoored, and rates of suicide, loneliness and chronic illness continue to skyrocket. How do we explain the gap between these truths? And how should we respond? For evolutionary biologists Heather Heying and Bret Weinstein, the cause of our woes is clear: the modern world is out of sync with our ancient brains and bodies. We evolved to live in clans, but today many people don't even know their neighbours' names. Survival in our earliest societies depended on living in harmony with nature, but today the food we eat, the work we do – even the light we absorb – is radically different from what our minds and bodies evolved to expect. In this book, Heying and Weinstein draw on decades of their work teaching in college classrooms and exploring earth's most biodiverse ecosystems to confront today's pressing social ills – from widespread sleep deprivation and dangerous diets to damaging parenting styles and backward education practices. A Hunter-Gatherer's Guide to the 21st Century outlines a science-based worldview that will empower you to live a better, wiser life.

Leseprobe

A Hunter-Gatherer’s Guide to the 21st Century

SWIFT PRESS

First published in the United States of America by Penguin Random House 2021 First published in Great Britain by Swift Press 2021

Copyright © Heather Heying and Bret Weinstein 2021

The right of Heather Heying and Bret Weinstein to be identified as the Author of this Work has been asserted in accordance with the Copyright, Designs and Patents Act 1988.

A CIP catalogue record for this book is available from the British Library

ISBN: 978-1-80075-074-6

eISBN: 978-1-80075-075-3

Book design by Daniel Lagin

Neither the publisher nor the author is engaged in rendering professional advice or services to the individual reader. The ideas, procedures and suggestions contained in this book are not intended as a substitute for consulting with your doctor. All matters regarding your health require medical supervision. Neither the author nor the publisher shall be liable or responsible for any loss or damage allegedly arising from any information or suggestion in this book.

To Douglas W. Heying and Harry Rubin, who saw so much, so early, and with such clarity

Contents

Introduction

1. The Human Niche

2. A Brief History of the Human Lineage

3. Ancient Bodies, Modern World

4. Medicine

5. Food

6. Sleep

7. Sex and Gender

8. Parenthood and Relationship

9. Childhood

10. School

11. Becoming Adults

12. Culture and Consciousness

13. The Fourth Frontier

Epilogue

Afterword

Acknowledgments

Glossary

Recommended Further Reading

Notes

Introduction

In 1994, we spent our first summer in graduate school at a tiny field station in the Sarapiquí region of Costa Rica. Heather was studying dart-poison frogs; Bret homed in on tent-making bats. Every morning we did fieldwork in the rain forest, where it was green and lush and dark.

We remember a particular afternoon in July. A pair of macaws flew overhead, silhouetted against the sky. The river was cool and clear, and trees full of orchids crowded the bank. It was a perfect antidote to the sweat and heat of the day. On beautiful afternoons like this one, we would walk across the paved road that went all the way to the capital, onto a smaller dirt road, and cross a steel bridge that spanned the Río Sarapiquí, to take a swim at the beach below.

We paused on the bridge to admire the view: the river wending its way between walls of forest, a toucan flying between trees, the distant calls of howler monkeys. A local man whom we did not know approached and began talking to us.

“You are going to swim?” he asked, pointing at the sandy bank where we were headed.

“Yes.”

“Today there was rain in the mountains,” he said, pointing to the south. The river’s source was in those mountains, in the cordillera. We nodded. Earlier, we had seen the thunderclouds above the mountains from the field station. “Today there was rain in the mountains,” he said again.

“But no rain here,” one of us said, laughing lightly, not knowing how to make small talk in a language we weren’t fluent in, while standing on a bridge, eager to swim.

“Today there was rain in the mountains,” he said a third time, more emphatically. We looked at each other. Perhaps it was time to take our leave, to walk down to the river and get in the water. The sun was now directly on us. It was desperately hot.

“Okay, see you later,” we said, waving, moving on. We were barely fifty feet from getting in the water.

“But the river,” the man said to us, now with some urgency.

“Yes?” we asked him, confused.

“Look at the river,” he said, pointing. We looked down. It looked like the river always did. Running fast and clean, smooth and . . .

“Wait,” said Bret. “Is that a whirlpool? That wasn’t there before.” We looked at the man again, questions in our eyes. He pointed again to the south.

“Today there was a lot of rain in the mountains.” He moved his focus back to the river. “Look at the water now.”

In the moments we had been looking away, the water had come up visibly. It was moving chaotically, roiling. It had changed color, too—from dark and calm, it had become pale and filled with silt. In short order, it was filled with more than that.

The three of us stood transfixed, as the river rose spectacularly, many feet in just a few minutes. The beach disappeared under a huge volume of rushing water. Anyone on it would have been swept away. Debris, including several logs, began to hurtle past. Anything that hit that new whirlpool disappeared, then shot back up beyond the bridge.

The man turned around and began to walk off the way that he had come. He was a campesino, a farmer, but we didn’t know where he was from, or how he knew that we were there, about to descend to what could easily have been our deaths.

“Wait,” Bret called, then realized that we had nothing to offer him but gratitude. We literally had nothing on us but our clothes. “Thank you,” we said. “Thank you so much.” And Bret took off his shirt and gave it to the man.

“Really?” the man asked, as Bret held out his shirt.

“Really,” Bret confirmed.

“Thank you,” he said, accepting the shirt. “Good luck. And remember to think about the rain in the mountains.” With that, he left.

We had been living by that river for a month, swimming in it nearly every day, sometimes alongside local people. Suddenly, we felt like strangers. We’d mistaken our few experiences swimming in the river for the wisdom of actually knowing a place. How could we have been so wrong?

At no other time in history has it been possible to think that you are a local but to be so lacking the deep knowledge of a place that keeps you safe during rare events. We moderns struggle to grasp this gap in our knowledge for many reasons. For starters, we no longer rely on tight-knit communities or a deep understanding of local terrain like humans did until recently. Given how easy it is to move from place to place with relative ease, many people tend not to stay in one locale for long at all. The facts of our individualistic lifestyles and transience tend never to strike us as odd, simply because we’ve neither seen nor can imagine an alternative to the world we live in right now: one where abundance and choice are ubiquitous, we rely on global systems too complex to understand, and everyone feels safe.

Until they don’t.

The truth is, safety too often proves to be a facade: products on supermarket shelves turn out to be dangerous; a frightening diagnosis reveals weaknesses in a health-care system too focused on symptoms and profits; an economic downturn stresses a disintegrating social safety net; legitimate concerns about injustice become excuses for violence and anarchy while civic leaders offer pablum rather than solutions.

The problems that we face today are both more complex and simpler than experts make them seem. Depending on whom you’ve asked, you may have heard that we are living in the best, most prosperous time in human history. You may have also heard that we are living through the worst and most dangerous time. You may not know which side to believe. What you do know is that you can’t seem to keep up.

Over the past few hundred years, developments in technology, medicine, education, and so much more have accelerated the rate at which we are exposed to change in our environments—including our geographic, social, and interpersonal environments. Some of this change has been wildly positive, but hardly all, and other changes appear positive but have consequences so devastating that, once discovered, we struggle even to conceptualize them. All of this has encouraged the postindustrial, high-tech, progress-oriented culture we live in now. This culture, we propose, partially explains our collective troubles, from political unrest to widespread failing health and broken social systems.

The best, most all-encompassing way to describe our world is hyper-novel. As we will show throughout the book, humans are extraordinarily well adapted to, and equipped for, change. But the rate of change itself is so rapid now that our brains, bodies, and social systems are perpetually out of sync. For millions of years we lived among friends and extended family, but today many people don’t even know their neighbors’ names. Some of the most fundamental truths—like the fact of two sexes—are increasingly dismissed as lies. The cognitive dissonance spawned by trying to live in a society that is changing faster than we can accommodate is turning us into people who cannot fend for ourselves.

Simply put, it’s killing us.

In part, this book is about generalizing this message to all aspects of our lives: when it rains in the mountains, stay out of the river.

Many people have attempted to explain the cultural dissolution we face, but most have failed to provide a holistic explanation that not only examines our present, but also looks back into our past—our whole past—and into the future. We are evolutionary biologists who have done empirical work on sexual selection and the evolution of sociality, and theoretical work on the evolution of trade-offs, senescence, and morality. We are also married to each other, have a family together, and have often been side by side while exploring many parts of the globe. Well over a decade ago, when we were still college professors, we began formulating the idea for this book. We stood on the shoulders of giants—our mentors and senior colleagues, as well as many intellectual ancestors whom we never met—but were also building curriculum that was unlike any that came before. We forged new paths, and posited new explanations for patterns, both old and new. We came to know our undergraduate students well, and as they engaged our curricula, they asked questions across domains: What should I be eating? Why is dating so difficult? How do we create a more just and free society? The common threads throughout these conversations—in classrooms and labs, in jungles and around campfires—were logic, evolution, and science.

Science is a method that oscillates between induction and deduction—we observe patterns, propose explanations, and test them to see how well they predict things we do not yet know. We thus generate models of the world that, when we do the scientific work correctly, achieve three things: they predict more than what came before, assume less, and come to fit with one another, merging into a seamless whole.

Ultimately, in this book and with these models, we seek a single, consistent explanation of the observable universe that has no gaps, takes nothing on faith, and rigorously describes every pattern at every scale. This goal almost certainly cannot be attained, but there is every indication that it can be approached. Though we may glimpse this end point from our modern perch, we are a long way from reaching the limits of what can be known.

That said, we are much closer to the goal in some areas than in others. In physics we seem tantalizingly near a “theory of everything,”1 which really means a complete model of the least complex, most fundamental layer of explanation. As we move up in complexity, things become less and less predictable. Near the top of the stack we reach biology, where processes inside even the simplest living cells are nowhere near fully understood. Things only get more complex from there. As cells begin to function in coordinated ways, becoming organisms made up of distinct tissues, the degree of mystery compounds. The unpredictability jumps again in animals, governed by sophisticated neurological feedbacks that themselves investigate and predict the world, and once again as animals become social and begin to pool their understanding and divide their labor. Nowhere are we more regularly stumped than we are in understanding ourselves. We Homo sapiens are brimming over with profound mysteries—surrounded by paradoxes born of the very things that make us distinct from the rest of the biota.

Why do we laugh, cry, or dream? Why do we mourn our dead? Why do we make up stories about people who never lived at all? Why do we sing? Fall in love? Go to war? If it’s all about reproduction, why do we take so many years to get on with it? Why are we so picky about with whom we choose to do it? Why are we fascinated by the reproductive behavior of others? Why do we, sometimes, choose to impair and disrupt our own cognition? The list of human mysteries is endless.

This book will address many of those questions. It will bypass others. Our primary aim here is not to simply answer questions but to introduce you to a robust scientific framework for understanding ourselves, one we have developed over decades of study and teaching on the topic. It is not a framework you will find elsewhere; we developed it by working from first principles as much as possible.

First principles are those assumptions that cannot be deduced from any other assumption. They are foundational (like axioms, in math), and so thinking from first principles is a powerful mechanism for deducing truth, and a worthy goal if you are interested in fact over fiction.

Among the many benefits of first principles thinking is that it helps one avoid falling prey to the naturalistic fallacy,2 which is the idea that “what is” in nature is “what ought to be.” The framework that we present here is built to free us from these sorts of traps. It is intended to allow us humans to make sense enough of ourselves that we can, at a minimum, protect ourselves from self-inflicted harm. In this book, we will identify the most large-scale problems of our time, not through the limiting, divisive lens of politics, but through the indiscriminate lens of our evolution. One of our hopes is that we can help you to see through the noise of our modern world and become a better problem solver.

Modern Homo sapiens arose approximately two hundred thousand years ago, the product of 3.5 billion years of adaptive evolution. We are, in most ways, a generic species. Our morphology and physiology, though stag-gering and marvelous when considered in isolation, are not special when compared to those of our nearest relatives. But we, uniquely, have transformed the globe and become a threat to the planet on which we still thoroughly depend.

We might have called this book A Postindustrialist’s Guide to the 21st Century. Or An Agriculturalist’s Guide. Or A Monkey’s Guide, or A Mammal’s Guide, or A Fish’s Guide. Every one of those represents a stage of evolutionary history to which we have adapted, and from which we carry evolutionary baggage: our Environment of Evolutionary Adaptedness, or EEA, to use the term of art. In this book, we speak to our Environments of Evolutionary Adaptedness—which is to say, not just the EEA of the title, such as the African grasslands and woodlands and coasts on which our ancestors were hunter-gatherers for so long, but the many other EEAs to which we are adapted. We emerged onto land as early tetrapods; became lactating, fur-bearing mammals; developed dexterity with our hands and visual acuity as monkeys; grew and harvested our own food as agriculturalists; and live cheek to jowl with millions of anonymous others as postindustrialists.

We chose to include hunter-gatherer in the title of the book because our recent ancestors spent millions of years adapting to that niche. This is the reason so many people romanticize this particular phase of our evolution. But there was not just one hunter-gatherer way of life, any more than there is one mammalian way of life, or a single way to farm. And we are not adapted only to being hunter-gatherers—we also adapted, long ago, to being fish; more recently, to being primates; and most recently, to being postindustrialists. All of these are part of our evolutionary history.

This wide-ranging view is necessary if we are to understand the biggest problem of our time: Our species’ pace of change now outstrips our ability to adapt. We are generating new problems at a new and accelerating rate, and it is making us sick—physically, psychologically, socially, and environmentally. If we don’t figure out how to grapple with the problem of accelerating novelty, humanity will perish, a victim of its success.

This is a book not only about how our species is in danger of destroying our world. It is also about the beauty humans have discovered and created, and how we can save it. An irrefutable evolutionary truth undergirding this book is that humans are excellent at responding to change and adapting to the unknown. We are explorers and innovators by design, and the same impulses that have created our troublesome modern condition are the only hope for saving it.

A Hunter-Gatherer’s Guide to the 21st Century

Chapter 1

The Human Niche

It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness, it was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness, it was the spring of hope, it was the winter of despair, we had everything before us, we had nothing before us.

Charles Dickens, from the opening lines of A Tale of Two Cities, published in 1859, the same year that Charles Darwin published On the Origin of Species

Beringia was a land of opportunity, a vast and open Grassland. A landmass four times the size of California that connected Alaska to the east with Russia to the west, Beringia was not merely a temporary land bridge, a passage between Asia and the Americas. People did not scurry across, the rising waters lapping at their feet, nor was it a lifeless plain. Life was surely difficult, but for thousands of years, Beringia supported a population of people who made their home there.1

The people who came to Beringia were fully modern in every genetic and physical sense. They came from the west, from Asia, and for a long time there was a barrier of ice at Beringia’s eastern edge. So they settled there, and many generations passed. As the world warmed, though, the ice began to melt, sea levels rose, and Beringia began to disappear, the coastline encroaching on what had been home. Where to go?

Artist’s rendering of Beringia based on Bond, J. D., 2019. Paleodrainage map of Beringia. Yukon Geological Survey, Open File 2019-2.

Some Beringians no doubt went west, back to Asia, from where all of their ancestors had come, a land that may have lived in myth and collective memory. Perhaps in the intervening years, newer arrivals had come from there, too, and brought with them updated stories of what their home to the west was like.

As sea levels rose on the Beringians, some headed east, into a land that no humans had ever seen before. These were the first Americans. Probably the Beringians traversed that northern part of the west coast by boat.2 The ice was still there, but there would likely have been ice-free refugia peppering the coast, places where local animals concentrated, places that may have acted as stepping-stones for those first Americans.3

This was, best estimates now suggest, at least fifteen thousand years ago,4 and possibly far deeper into history even than that. Depending on what that ice sheet looked like, perhaps they couldn’t make permanent landfall until they got as far south as what is now the city of Olympia, in Washington State. It was there that the glaciers ended. South of Olympia, and east, landmasses unimaginable in their scope and variety, full of verdant and beautiful landscapes and delicious and charismatic or-ganisms, but no people, were about to be explored by humans for the first time.

It was a risky move. The whole thing was incredibly risky. None of the choices seemed good. Go back to the west, to a land already occupied by people who undoubtedly have opinions about newcomers? Head east, to a land nobody knows anything about? Or stay in place as Beringia disappears into the sea? Nobody who survived chose the third option. Go back to what your people once knew, a place vetted and abandoned by your ancestors, a place known to be full of competitors . . . or explore someplace completely new? Both are legitimate choices, both have distinct risks, distinct advantages and disadvantages. These are, likewise, the options in our modern world.

The descendants of the Beringians would come to populate the Americas in total isolation from all human populations in the Old World. They arrived before any humans on Earth had invented written language or agriculture; independent of any input from their Old World relatives, they innovated these things from scratch. Their lineage would discover hundreds of new ways of being human, and rise to an estimated population of fifty million to one hundred million before Spanish conquistadors brought the Old and New World populations into violent reconnection many thousands of years later.

We do not know for certain what the journey to the New World looked like. Perhaps the first Americans were even earlier, not making permanent homes in Beringia at all, instead circumnavigating the Pacific, clockwise, in boats.5 What we do know is that the New World presented challenges that the first Americans had never seen before. And this story of Beringia, even if true only at the metaphorical level, is instructive of what it is to be human. It is an apt if incomplete metaphor for the situation that humanity is in today. We too find ourselves in a failing land. We too must seek new opportunities to save ourselves. And we too do not yet know what exploration will yield.

Early Americans found themselves in an immense landscape of unknown hazards and opportunities. With ancestral knowledge that was ever less relevant as a guide, the challenges of navigating this new world would have been immense. And yet they succeeded spectacularly. The question that we ask, and which is most pertinent to our modern situation, is How? The answer will be found, in large measure, in understanding what it is to be human.

Several generations in, sitting around the fire at night, a bit hungry because berry season was past its peak and the deer had grown scarce, one of these early Americans, call him Bem, might have observed that bears seem to sustain themselves on the fish, so why can’t we?6 Bem didn’t know much about fish, though, not like Soo, who had spent many days at river’s edge, watching fish, and had insight about how the fish behaved. Soo’s insight about fish was, heretofore, not one she had shared, nor one that had seemed to her likely to have any value to her people. Soo, in turn, may not have had latent engineering skills, as Gol did, and Gol may have lacked Lok’s talent in experimenting with making rope. When so many people with distinct talents and insights come together around a camp fire to discuss a shared problem, the spark of innovation can spread quickly.

Most of the best ideas that our species has generated, the most important and powerful ideas, have been the result of a group of people who had different but consilient talents and vision, non-overlapping blind spots, and a political structure that allowed for novelty. Gathered around the fire at the threshold of two continents new to humanity, many insightful observers and engineers, crafters of tools and synthesizers of information, came together and learned, or relearned, how to fish salmon from rivers, what bulbs were safe to eat and how to identify them, and how to transform trees into shelter. Those populations had keepers of the flame, too: holders of tradition, individuals who would tell the story later, perhaps when a move was necessitated by the failure of a local salmon run and all of the original innovators were gone.

What all were Bem or Soo or Gol or Lok doing, exactly? They were innovating, as part of and on behalf of their people. They were testing hypotheses, creating narrative, building material and culinary traditions. They were being human.

The Human Paradox

Twenty-first-century people face opportunities and dilemmas similar to those of the original people of the New World. Innovations in technology and science have allowed us to enter new, previously unimagined realms. But unlike the Beringians, we do not have an ancestral land to even consider returning to, because our actions affect the entire planet. We have hunted and gathered, cultivated and machined our way around the globe, transforming the earth in our wake, bending landscapes to our will and pushing many to the brink of collapse.

Some look back at our species’ successes, such as the success of the Beringians, and imagine that we can master nature, that we are in control of it. But we are not, and we never will be.7 The consequences of this bad assumption account for many of our problems today. The only way to course correct is to understand the true nature of what we are, what we might be, and how we might apply this wisdom to our benefit.

Our species is brainy and bipedal, social and talkative. We make tools, cultivate land, produce myth and magic. We have reinvented ourselves over time and across space, over and over again, learning to dominate one habitat after another. Species are defined by many things—their form and function, their genes and development, their relationship to other species. Perhaps most important, though, species are defined by their niche: the particular way they interact with and find a way to make a living in their environment.

Given our breadth of experience and geography, what exactly is the human niche?

As our species has evolved, we seem to have escaped a fundamental law of nature: the jack-of-all-trades is the master of none. To be dominant in any one niche, a species must typically specialize, sacrificing breadth and generality. It is this need to specialize that hobbles the jack-of-alltrades, a principle so universal that it has been invoked for more than four centuries in print (one of the earliest instances being a 1592 jab at actor-turned-playwright William Shakespeare).8 “The jack-of-all-trades is the master of none” is applied broadly, from engineering to sports to ecological science. Species are, in this way at least, like tools: the more jobs they do, the more crudely they do them.

Yet somehow here we are, jacks of nearly every trade imaginable, and simultaneously the masters of nearly every habitat on Earth. Our niche is nearly unbounded, and when we do find boundaries, we nearly immediately begin to test them. It’s as if we don’t believe there will ever be a final frontier.

Homo sapiens is not merely exceptional. We are exceptionally exceptional.9 Unrivaled in our adaptability, ingenuity, and exploitative capacity, we have come to specialize in everything over the course of hundreds of thousands of years. We enjoy the competitive advantage of being specialists, without paying the usual costs of a lack of breadth.

This is the paradox of the human niche.10

A paradox in science is like an X on a treasure map: It tells us where to dig. Our unrivaled breadth of specialization is a paradox that marks the location of a spectacular trove, not so much of riches, but of tools. By unraveling the human paradox, we can unlock a conceptual framework that allows us to understand ourselves, and to navigate our lives with intention and skill. This book unpacks the human paradox, and describes the tools we discover there; it is also an exercise in their application.

Campfire

In our discussion of the first Americans, we have already seen one tool in this treasure trove, though it might not seem to be a tool at all. It is a campfire.

Humans have been using fire for eons. We have used it to make light and create warmth, to increase the nutritional value of food, and to keep predators at bay. We have used fire to hollow logs to make canoes, to transform landscapes to new purposes, to soften and harden metal. We have also used fire for something even more important: The campfire is a forge for ideas. A place to discuss berries, rivers, and fish. A place to share our experiences, to talk, to laugh, to cry, to deliberate over our challenges and share our successes. From this forge emerge the kinds of ideas that render humans a true superspecies, one that surfs the rules of the universe, kicking up paradoxes in its wake.

The exchange of ideas that has occurred around the hearth for millennia is more than simple communication. It is the convergence point of individuals with different experience, talent, and insight. The linking of minds is at the root of humanity’s success. It doesn’t matter how smart an individual is, and it doesn’t matter how much they know. In nearly every case, when minds come together, the whole is greater than the sum of its parts. For the problems that humanity faces—from which bulbs are safe to eat and how to catch rabbits, to how to equalize opportunity while creating a world that is safe from existential threats—we need more than individuals processing in isolation. If we are to survive the future, we need multitudes of people plugging in and parallel processing. Joining minds in this way exponentially increases the ability of humans to solve problems.

Just as humanity broke down boundaries between niches that no other organism has broken down, so too have we broken down boundaries between individuals that nothing else has broken down so thoroughly. With regard to niches, we are a generalist species that contains individuals who are often specialists. A single ancient American may have been terrific at wayfinding, but terrible at keeping the flame. A single modern human may be terrific at rock climbing but terrible at organizing their files, or excellent with numbers but unskilled in the baking of bread. As a species, though, we are supremely good at all of these things. It is the connections between us that allow us to transcend our individual limitations, often focusing on our trade while being sustained by the specialized labor of others.

At the boundaries between individuals, we consciously innovate and share ideas, and then reify the best and most relevant of those ideas for the current moment in the form of culture. For millennia, this magic has occurred around the common campfire.

Consciousness and culture—themes that we return to in depth in the penultimate chapter of this book—are in tension with each other, and humans need both.

Conscious thoughts are those that can be communicated to others. We define consciousness, therefore, as “that fraction of cognition that is packaged for exchange.” This is no trick. We have not chosen a definition to make an intractable question simple. We have chosen the definition at the epicenter of what people mean when describing a thought as “conscious.”

One truth that emerges from understanding consciousness in this way is that it makes little sense to assume that individual consciousness evolved first, or that it is the most fundamental form of consciousness. Rather, our individual consciousness likely evolved in parallel with collective consciousness, and would become fully realized only later in our evolution. Understanding what is in the mind of another—known as theory of mind—is staggeringly useful. We see the rudiments of this capacity in many other species, and we see it extensively elaborated in a highly cooperative few, such as elephants, toothed whales (such as dolphins), crows, and many nonhuman primates. We humans are by far the most aware of one another’s thoughts of any species that has ever existed, because we alone can, if we so choose, hand over the cognitive goods explicitly and with spectacular precision. We can accurately pass a complex abstraction from one mind to another by simply vibrating the air between us. It is everyday magic that usually passes without our notice.

For theory of mind to function, one needs to run an emulation of the other person within one’s own head. For me to benefit from a comparison between what I think on the one hand and what I understand you to think on the other, I am all but required to have subjective experience of both you and me—to bring the two into a single currency. Shared consciousness is an emergent, intangible space between people, where concepts are lodged and co-cultivated. Each participant has a distinct perspective on the space, much as each witness to a physical event will have a somewhat different vantage point, but the space is a property of the collective.

Imagine two populations composed of equally smart individuals. In the first population, individuals cannot just propose ideas, but also must respond to and modify the ideas of others, and then strategize and plan how to act on them, with each individual contributing in his or her own area of specialty. The second is made up of individuals who, while full of good ideas themselves, have no ability to conceptualize what others are thinking. When these two populations are in competition with each other, there is simply no contest.

Even a rudimentary collective consciousness—what might be shared between wolves in a pack, for example, as they are hunting cooperatively—provides a staggering advantage. In lions, too, the pride is far greater than the sum of its individuals. Collective consciousness, an evolutionary innovation unlike any other, creates cognitive emergence.

Culture versus Consciousness

Consciousness is valuable for problem-solving, but it isn’t so good for execution. The gymnast, the virtuoso, and the warrior all succeed by taking what they have discovered consciously and learning to apply it without explicit deliberation.11 Transformative insights and ideas move out of the conscious layer and into the parts of us that know how to get things done. When one is in the zone, the conscious mind is present, but as a spectator who steers clear so as not to disrupt the flow. Behaviors become habitual and intuitive. In an individual, we might call this skill or craft. In a family or a tribe, such habits become traditions, passed efficiently from one generation to the next. Scale this up further, and we have culture.

Homo sapiens therefore oscillate between two dominant modes. When we face problems for which our prior understanding is inadequate, we become conscious. How do we feed ourselves in this new land? We plug our minds into a shared problem-solving space and share what we know. Then we parallel process—proposing hypotheses, providing observations, offering challenges—until we arrive at a new answer, one that an individual would rarely reach alone. If the result works well when tested in the world, it gets refined and then driven into a more automatic, less deliberative layer. This is culture. The application of culture to the circumstances for which it is adapted is the population-level equivalent of an individual being in the zone.

This model implies a few important things. When times are good, people should be reluctant to challenge ancestral wisdom—their culture. In other words, they should be comparatively conservative. When things aren’t going well, people should be prone to endure the risks that come with change. They should be comparatively progressive—liberal, if you will.

This of course has a lot to say about the modern world, because for various reasons, there is little agreement at present on how well things are going. Moments before the Titanic hit the iceberg, the ship was a marvelous testament to human achievement. Moments after, it was a monument to the hazard of hubris. Too often, it is only in retrospect that the rearranging of deck chairs appears absurd. More often than not, there is no iceberg, no clear demarcation of before and after, of the moment when consciousness should become more salient than culture.

Humans break

1. niche boundaries by being both generalists and specialists.

2. interpersonal boundaries by oscillating between culture and consciousness.

The financial collapse of 2008, Deepwater Horizon oil spill, and the Fukushima Daiichi nuclear disaster are all symptoms of a civilization-level disorder, one that has no name. Let’s call it the Sucker’s Folly: the tendency of concentrated short-term benefit not only to obscure risk and long-term cost, but also to drive acceptance even when the net analysis is negative.12 These events are evidence that we are resting on our cultural laurels and speeding toward disaster, lulled into a false sense of security—and away from collective consciousness—by the opulence of our surroundings. The sooner we recognize this, the greater the chance to divert the ship to a safe course, a puzzle we will return to in the last chapter of this book.

The answer to our earlier question, then—What is the human niche?—is this: Humans don’t have a niche, not in the standard sense of that term. We have escaped the paradigm by mastering a different game. We have discovered how to swap out our software and replace it as the need arises by oscillating between culture and consciousness. The human niche is niche switching.

Humanity is the master of every trade. If we were machines, we would be ones that are compatible with many software packages. The Inuit hunter knows the Arctic, but has few of the skills needed to function in the Kalahari or the Amazon. Humans can be good at almost anything, given the proper tools and software, and human populations can be good at many things by virtue of a division of labor, but each individual person will either have to limit themself or accept the costs that come with being a generalist.

As our world becomes increasingly complex, though, the need for generalists grows. We need people who know things across domains, and who can make connections between them: not just biologists and physicists, but biophysicists; people who have switched gears and found that the tools they brought from their prior vocation serve them well in a new one. We must find ways to encourage the development of generalists. In this book, we argue that a key way to do this is to encourage a careful, nuanced understanding of what evolution is, what it has made us, and how we can resist its goals. To that end, let us first, in the remainder of this chapter, provide a few updates to evolutionary theory. The alterations that we are suggesting open a path to understanding evolution more deeply, and also to understanding ourselves, our cultures, and our species.

Adaptation and Lineage

Adaptive evolution improves the “fit” of creatures to their environment. This is well established. In a rush to make evolutionary biology an empirical science, though, biologists prioritized defining fitness such that it could be easily measured. We biologists settled on a definition that is almost synonymous with reproduction. As is the case with many assumptions that ultimately fail, the belief that fitness and reproductive success were near synonyms was wildly successful at first, enough so that generations of biologists made great headway by simply treating them as one. All else being equal, a creature that is a better fit for the environment tends to produce more offspring, and when that is the case, biologists have excellent conceptual tools for unpacking the evolutionary process that leads to it. What happens when all else isn’t equal, however, and the creature with more offspring has cut corners in the pursuit of short-term fecundity? Under these conditions the ability of biologists to understand the story is compromised. If the harm done to fitness shows up quickly—if an individual animal produces many offspring, all of which perish in the winter—we will likely come to understand that it failed in an evolutionary sense. If, however, the descendants prosper for a fairly long time, but die off in the next drought, or the next Ice Age, there is a good chance biologists will botch our analysis of “success.”

Fitness is indeed often about reproduction, but it is always about persistence. A successful population can ebb and flow through time. What a successful population can’t do is go extinct. Extinction is failure. Persistence is success—and the reproduction of individuals is only one factor in the persistence equation.

But what does it mean to persist? Is it species persistence we are after? Do we count each population within the species separately? Is it an individual’s descendants we should be counting? Logically, it must be all of those things, and more.

Adaptive evolution occurs as individuals compete for resources. Each individual is the beginning of a line of descent, and the period over which its descendants persist is a good proxy for its fitness. If Bem’s descendants perish as the glaciers return, but Soo’s descendants find their way through to the next interglacial, the latter were fitter—whether we were able to measure the difference or not.

But those two individuals were not only the starting points for lines of descent going forward. Each was also a member of many simultaneous, overlapping lines of descent stretching backward to a large collection of ancestors about whom we could say the same thing. So if fitness is about persistence, then the apropos question is, The persistence of what?

This is where we must break our sense of obligation to measure things. Adaptive evolution—the process that increases the “fit” of creatures to environment—is about all levels of descent at once. Adaptive evolution is therefore fractal, and the term that encapsulates it is lineage.

An individual and all of its descendants comprise a lineage. A species is a lineage descended from that species’ most recent common ancestor—as too are larger clades, such as mammals, vertebrates, animals—lineages descended from those clades’ most recent common ancestors.13 Our job as evolutionary biologists is to figure out how adaptive evolution works with selection at all levels of lineage occurring simultaneously. In this book we will proceed from the premise that lineages compete, and those that are better suited to their long-term environment are favored by selection. That buys us a lot in terms of illuminating the paradoxes of human nature, but it’s far from sufficient. We must also recognize that, contrary to conventional evolutionary wisdom, genes are not the only form of heritable information.

Culture evolves. Furthermore, culture evolves in tandem with the genome, and is obligated to the same objective. We need not know the degree to which, for example, sex-typical behaviors like female nesting or male bravado are transmitted culturally or genetically; the mode of transmission says nothing about the meaning of these patterns. Whether cultural, genetic, or a mixture of the two, sex roles inherited from a long line of ancestors are biological solutions to evolutionary problems. They are, in short, adaptations that function to facilitate and ensure lineage persistence into the future.

This is a hard pill for many to swallow, but the truth is that culture exists in service to the genes. Long-standing cultural traits are as adaptive as eyes, leaves, or tentacles.

In the 21st century, nearly everyone accepts that evolution has created our limbs and our livers, our hair and our hearts. Yet many people still object when evolutionary theory is invoked to explain behavior or culture.14 Even for many scientists, this position is driven by the belief that some questions should not be asked if the answers to them might be ugly. This has led to ideologically driven censorship of ideas and research programs, which has slowed the rate at which we have enhanced our understanding of who we are, and why.

Some of what evolution has produced is, indeed, ugly: infanticide, rape, and genocide are all products of evolution. It is also true that much of what evolution has produced is beautiful: a mother’s sacrifice for her child; enduring romantic love; and civilization’s care for its citizens, young and old, healthy and not. A widespread lack of understanding of what it means for something to be “evolutionary” explains the concern that some people have.

Many people fear that if something is evolutionary it must be immutable. If that were true, then if something horrible is the product of evolution we would be powerless against it, and would be forced to suffer the cruelty of evolutionary fate forevermore. Fortunately, this fear is wrong. Some of what is evolutionary is nearly invariant: humans have two legs, one heart, a large brain. But the variation between individuals is also evolutionary, and strongly dependent on interactions with our environment: how long are our legs, how strong are our hearts, how interconnected are the neurons in our brains? Similarly, recognizing the evolutionary truth that women are both more agreeable than men, on average, and more anxious is neither a diagnosis of any individual nor an immutable fate. Individuals are not the same as populations.15 We are individual members of populations, and those populations—men and women, boomers and millennials, Americans and Australians—have real psychological differences, but we are more similar than dissimilar. Those differences are the results of interactions between multiple layers of evolutionary forces. Furthermore, humans have the ability to directly plug in to one another and alter our culture, for both better and worse.

In response to the widespread confusion surrounding cultural and genetic evolution, we have developed a simple model for understanding the hierarchical nature of the forces at play. We call it the Omega principle.

The Omega Principle

Epigenetic means “above the genome.” The first time either of us encountered the term was in college in the early ’90s. At that time it was occasionally used by evolutionary biologists to place culture in a rigorous evolutionary context.

Culture sits “above” the genome in the sense that it shapes the way the genome is expressed. Genes describe proteins and processes that construct a body. Culture—in those creatures that have culture—has a powerful influence on where bodies go, and what they do. In this way, culture is a regulator of genome expression.

The term epigenetic has in more recent decades taken on a different meaning. The term is now almost exclusively used to refer to mechanisms that directly—molecularly—regulate the expression of the genome—expressing some traits while suppressing others, creating the patterns of gene expression that give the body a coherent form and function. These regulatory mechanisms, which scientists are just beginning to understand, are the key to understanding multicellular life. Without these mechanisms, all cells with a given genome would be alike, and any large collection of cells could exist only as a colony of undifferentiated cells. It is only through the tight, epigenetic regulation of gene expression that we can have an animal or a plant composed of well-coordinated, distinct, multicellular tissues.

While the meaning of the term epigenetic has gone through a radical transformation, from describing inherited behavior to describing only molecular switches, a strong argument can be made that the category of epigenetic phenomena actually includes both types of regulators: molecular switches are the narrow meaning of the term—epigenetic sensu stricto (“in the strict sense”), while the molecular switches plus inherited behaviors are epigenetic sensu lato (“in the broad sense”).

Both are epigenetic, and the implication is that a single evolutionary rule governs both molecular and cultural regulators of gene expression.

Let’s take a Tibetan herdsman, as an example. He has an inherited culture that constrains his behavior. His cells take different forms and do different things based on inherited patterns of gene expression. It would make no sense to imagine that the genes in his genome and the molecular regulators that adjust their expression are rivals. If the herdsman is healthy, his cells serve his evolutionary interests as a creature—the regulation of his genes evolved to enhance his fitness. His eyes, composed of many kinds of cells distributed in particular ways, see danger and opportunity. The hazards he sees are threats to his evolutionary fitness, and the opportunities constitute ways in which he might enhance it. In other words, the genes and their regulators agree on the job to be done and show no sign of tension over it. What is the job of those genes and their regulators? It is obviously evolutionary—to lodge copies of the herdsman’s genes deeply into the future. No reasonable person would argue otherwise.

But many otherwise reasonable people will fail to see this relationship when it comes to the herdsman’s culture. He may adhere to gender roles that stretch back thousands of years in his lineage, but it is commonly asserted in scientific circles that these cultural patterns are not likely to be evolutionary, that they are “just cultural”—as if that were a competing category.

The problem stems from the initial, 1976 presentation of memetic evolution by Richard Dawkins in The Selfish Gene. As Dawkins describes memes—laying the foundation for the rigorous Darwinian study of cultural adaptation—he makes a fateful error. He describes human culture as a new primeval soup,16 in which cultural traits spread themselves much like genes do, rather than as a tool of the genome that evolved to enhance the genome’s fitness.

This misunderstanding has never been properly resolved, and the nature versus nurture confusion it engenders continues to block analytical and societal progress. Asking if a particular trait is due to nature or nurture implies a false dichotomy between nature, genes, and evolution on the one side and between nurture and environment on the other. In fact, all of it is evolutionary.

The key to seeing why culture must serve genes as a fitness-enhancing tool, exactly as molecular regulators do, is found in the logic of trade-offs, a concept to which we will return throughout the book.

From the genome’s perspective, culture is anything but free. In fact, nothing is more costly. The brain that picks up culture is big and energetically expensive to run; the process by which culture is transmitted is prone to error; and the content of human culture frequently blocks off fitness-enhancing opportunities—thou shalt not kill, steal, covet, lay with, etcetera. Anthropomorphizing the genome for a moment: If culture did not pay the genome back for its astronomical expense, the genome would have reason to be livid. Culture appears to waste time, energy, and resources that would otherwise be at the genome’s disposal. One might get the impression that culture is effectively parasitizing the genome.

But the genome is in the driver’s seat. A capacity for culture is nearly universal in birds and mammals; it has been elaborated, enhanced, and extended by genomic evolution over time; and it is at its most extreme in the world’s most broadly distributed and ecologically dominant species: humans. These facts tell us that whatever culture does, it is not coming at a cost to genetic fitness. Rather, it enhances fitness in dramatic ways. If culture was not paying its way, the genes whose expression it is modifying would either go extinct or evolve to be as immune to culture as an oak tree.

In our teaching of evolution to students, we have codified our understanding of the relationship between genetic and epigenetic phenomena in what we call the Omega principle. It has two elements:17

Omega Principle

1. Epigenetic regulators, such as culture, are superior to genes in that they are more flexible and can adapt more rapidly.

2. Epigenetic regulators, such as culture, evolve to serve the genome.

We have chosen to use the signifier Ω (omega) to call to mind π (pi), and thus indicate the obligate nature of the relationship. Adaptive elements of culture are no more independent of genes than the diameter of a circle is independent of that circle’s circumference.

From the Omega principle we derive a powerful concept: any expensive and long-lasting cultural trait (such as traditions passed down within a lineage for thousands of years) should be presumed to be adaptive.

Throughout this book, we will discuss such traits—from harvest feasts to the building of pyramids—through this evolutionary lens. We will use first principles to extrapolate what makes humans so special, and why the novelty of the modern era has made us mentally, physically, and socially unhealthy. In order to discover those principles, we must look for clues. In the next chapter, we will explore our deep history, touring the many forms we have taken, some of the many systems and abilities our ancestors innovated, and the human universals that unite us all.

Chapter 2

A Brief History of the Human Lineage

There are several human universals.1

All humans have language. We can tell self from other, and can distinguish self as subject (“I cooked for her”) from self as object (“she cooked for me”). We use facial expressions that are both general and nuanced, which include happiness, sadness, anger, fear, surprise, disgust, and contempt. We don’t just use tools; we use tools to make more tools.

We live in or under shelter. We live in groups, usually with family, and adults are expected to help socialize children. Children observe elders, and copy them. We also learn by trial and error.

We have status, governed by rules stemming from kinship, age, sex, and beyond. We have rules of succession and markers of hierarchy. We engage in division of labor. Reciprocity is important, both in the positive sense—barn raising for neighbors, exchanging gifts—and in the negative—retaliation for perceived wrongs. We trade.

We predict and plan for the future, or at least we try to. We have law, and we have leaders, although both may be situational or ephemeral. We have rituals, and religious practice, and standards of sexual modesty. We admire hospitality and generosity. We have an aesthetic, which we apply to our bodies, our hair, and our environment. We know how to dance. We make music. We play.

It took so long for us to become who we are today. If you look deeply into the history of life on our planet, you can see how these universals emerged over hundreds of millions of years, and once you understand this, you will see why change, especially rapid change, isn’t always such a good thing.

Three and a half billion years ago, give or take a few hundred million years, life blinked into existence on Earth. That organism was the common ancestor of all life on our planet, and we owe much to it, although we don’t resemble it much now.

The first single-celled organism had no nucleus. It had no sex. It made its own energy, perhaps by converting sunlight into food, as modern plants do, perhaps by converting inorganic molecules, such as ammonia or carbon dioxide, into food. As we move forward in history, as our ancestors get closer to us in time, we resemble them more and more closely.

Two billion years ago, our replicating material became encased in nuclei, allowing DNA to organize itself, such that careful unpacking, at the right moments, would trigger cascading events. Much complexity hides in the timing and coding of events—and in how things are packed. The ability to pack efficiently turns out to be important, for far more than suitcases and shipping containers. We were evolving so many ways to divide labor in that era—organelles within cells separated cellular functions from one another, micro-tubules and motor proteins began transporting cellular material around.

Now that we had cells with nuclei, we were eukaryotes, but we still lived alone, as single cells. A long time later, we began to associate more permanently with one another, combining forces, becoming multicellular individuals, rather than clusters of cells that aggregated.2 Specialization was crossing scales. Organelles within cells had long since innovated specialization—chloroplasts for photosynthesis, mitochondria for power—but the specialization had stopped at the boundary of the cell. Now, with multicellular organisms, life was leveling up.

Everyone who knows our deep history will have their favorite transformations, the ones that seem singularly important if anything downstream were to have a chance of happening. Perhaps you see the origin of brains, or of blood, or of bone, to be the evolutionary transformation on which all later innovations depended. All of them, except the earliest, hinge on conditions already created, so none of them were fated to be, in the form that we know them. In the beginning, there was the evolution of those who create their own energy. This made possible the evolution of those who take what others have created: heterotrophs, like us, who parasitize the energetic work of plants and other photosynthesizers. The particular way that we have evolved to be heterotrophs, to take the energy of others for our own—there was nothing inevitable about that.

Organisms, all of us, need to respire, to take in nutrients and excrete waste, to reproduce. The larger the organism, the more likely other things are needed, too: a plumbing system to move things around within the body; a control center—or centers—within which information is collected, interpreted, and acted upon.

More than six hundred million years ago we became multicellular individuals who steal energy from those who make it from the sun—we became animals.

Sex evolved in our lineage, and it has never gone away. Some traits blink on and off through evolutionary time—birds developed flight, and then some of them reversed course, became penguins, kiwis, ostriches.3 Snakes lost the limbs that their—and our—ancestors had developed over tens of millions of years. Even eyes, which provide the most dominant sense in humans, switch off in some species of cave fish, which live in waters so dark that eyes are no help, all hazard. In Mexican cave fish alone, there are dozens of distinct populations of eyeless forms, living near their sighted cousins on the surface.4

Other traits evolve once and then stick, suggesting that their value is nearly universal. No organisms that once evolved bony internal skeletons have since evolved a lifestyle without them. The same holds for neurons and for hearts. The evolution of sex—meaning, the evolution of sexual reproduction—isn’t quite so clean a story, but it is nearly so. There is one eukaryotic lineage known on earth that once had sexual reproduction and has since lost it. These are the bdelloid rotifers,5 which are highly unusual in several ways, including their ability to survive both extreme desiccation and high doses of ionizing radiation.6 But the lineage to which we belong is one long, uninterrupted string of sexual reproduction for at least the last five hundred million years.7

Early in our history as multicellular animals, some lineages branched into sessile forms—I will protect myself in place—others into mobile ones—I will rove the landscape searching for what I need, escaping from what wants me. Most of us are also bilaterally symmetrical: we have a left and a right, and the midline is a point of inflection, the views from either side a near mirror image of the other. Insects have a left and right, as do we vertebrates, although we are more closely related to sea stars than we are to insects. This reveals that even a patently useful trait like bilateral symmetry is not universally so—adult sea stars apparently gave up having a left and right in favor of radial symmetry.8

This evolutionary tree reflects our current understanding of the relationships between several extant taxa.9 Many taxa are excluded, but the nature of evolutionary trees is that you can exclude taxa without rendering a tree untrue; it’s just less complete.

This tree does not suggest that vertebrates are “more highly evolved” than anything else on the tree. This tree does suggest, among other things, that:

• Vertebrates and sea stars are more closely related to one another than either are to anything else on the tree.

•