Go Wild Read online

  The second image derives from a video readily available on YouTube, but anyone who has trained in developmental psychology has already seen it and heard it discussed at length, because its content explains a crucial issue of human development. But no need to go to the actual video: the scene it shows is normal enough and repeated often in every child’s upbringing, at least every child lucky enough to have a reasonably normal upbringing. The scene is easy to imagine. A mother and a toddler are alone in a room full of attractions and distractions for the toddler—brightly colored toys and other objects of fascination. But it’s a strange room. Toddler clings to mom but eyes attractions surreptitiously. Then courage builds, bolstered by mom’s affection, and toddler leaves mom to engage an attractive object, maybe a big block. The block falls and makes a noise, and toddler immediately bolts for mom, goes through an interval of comforting, and then works up the nerve to once more go exploring, to venture off in search of the unknown.

  All of this is exactly as it should be, now and from the beginning of human time. This pattern of balancing between comfort and exploration of the unknown is how we build our brains, and it is enabled by the presence of a mother’s affection and support. It is the normal state of affairs, and we will need this image later, because it is not just about toddlers; it is about each of us.

  The third image would at first blush seem to be about very few of us—a special case. We mean to address human well-being here as a universal, but autism is not universal. Most of us see it from afar and categorize it as one of those unlucky twists of fate that trouble a few people, maybe a genetic problem, but what has this to do with me? Yet we will build the case here that the relevance of this neurological problem goes well beyond the social costs. Autism may well be a disease of civilization, placing it right at the heart of the issues we trace here.

  We were particularly struck on a visit to the Center for Discovery, in upstate New York; it’s a residential facility that serves 360 people with autism, many of them too violent or disruptive to function in a normal family setting. Not all autistic people are violent or this disruptive, but the few who are wind up in places like the Center for Discovery. On the day we visited, staffers escorted us in and out of a series of classrooms, and we engaged some students without a second thought. Staffers told us that a month or so earlier this openness and access would not have been possible, that some of these people might have erupted. The staff credited the remarkable improvement in large part to an exercise regimen, and we watched people run, jump, and dance. This was their treatment: running, jumping, and dancing with one another. But just as important, this new routine built on a long-standing practice at the center of ensuring sound nutrition and connection with nature.

  The scene we keep coming back to, however, was in a single tiny classroom, where four adolescent boys were seated in a row facing a simple bell and wood block that they each played in turn. A slight, dark woman with a cherubic face and a pageboy haircut sat at a small electric piano and tickled out a simple refrain, over and over again, as repetitive and simple as it had to be to engage the boys to ring the bell or strike the block, each in strict simple time to the beat laid down by the piano player. The words of the refrain echoed the activity: “Ring the bell, ring the bell, ring the bell,” on and on and on. Rhythm and music, melody, meter, keeping time. This is the rhythm that calls forth a brain retreated from social engagement—the hallmark of autism.

  But then we noticed the piano player, that she must perform this repetitious exercise for hours on end each day, because that is what is required of her. We noticed, too, that she was not treating this like repetition, that she was putting something of herself into each phrase, throwing in little embellishments and improvisations, that she sang from her center and, like all good singers, from the core of her emotional self. She was summoning a ray of hope to make music—not just sound, not even just melody and rhythm, but music—and doing it again and again and again in a situation that most of us would find hopeless. She was every bit as engaged and invested with the circle around her as the !Kung San storyteller. She was living the moment. She was mindful.

  Appropriate, then, that this image came to us in this place, the Center for Discovery, because this was the site of one of two major turning points in each of our own stories. We have long said that there is no reason to write a book unless the process of doing so changes the author’s life. Forever. Fair enough, because we hope that this book will change your life. Eventually, we will report how this happened for each of us in detail. But up front, we can say that Richard Manning lost fifty pounds and became an ultramarathon trail runner. John Ratey lost some weight, too, and changed the way he eats every day—but the big change was a major expansion in what he thinks about. He is well-known for writing about exercise and the brain, but the compelling story that is emerging at the Center for Discovery has made him far more attentive to issues like sleep, food, nature, mindfulness, and—more important—how they work together to create well-being. But it’s not just the Center for Discovery that has changed John’s thinking. One chance meeting, and a remarkable, spontaneous, wrenching personal account, changed his life. We’ll get to that, too.

  1

  Human 1.0

  Why Evolution’s Design Endures

  Evolution has hard-wired health to happiness, which means happiness is not as hard to assess as we make it out to be—not if you approach it from the wild side. Ultimately, we don’t need someone else (or a book, for that matter) to define our happiness. Our brains do that. Every single aspect of the way we are wired and evolved makes it our brain’s job to tell us if we are okay. Our survival depends on it being so.

  Think of what our lives would be like if this were not true, if the body operated on perverse feedback loops that would tell us we are okay when we are, in biological terms, doing badly: we are hungry, cold, exhausted, and broken, and the brain says we are fine. Imagine such a feedback system, and then imagine the prospects of survival for an animal that has it. Imagine it being encoded and passed on in genes. But no need to imagine. This is precisely the perverse system that prevails in a drug addict, a hijacked system that says he is doing well when everybody can see he is not. Survival prospects? We know this answer without further study.

  What we need most to understand from this is that our happiness is greatly dependent on our biological well-being, and the conditions of that well-being have been laid down by the imperatives of survival, by evolution. All of this means we need to pay attention to the conditions of human evolution to ensure our happiness. But the problem is, we don’t. The popular understanding of human evolution is more or less wrong. But more important, the way we live is a clear and long-standing set of violations of the rules of human well-being, and it’s making us sick.

  First, summon that image that invariably pops into mind when we begin to think about human evolution: the series of cartoon panels in progression—first ape, then caveman, then us, and then a punch line. These ubiquitous cartoons make great jokes, but the idea behind them is wrong in an important way. So is the concept of a “missing link.” The cartoon supports the idea that evolution gradually produced modifications and changes in human design in one neat, clear progression from our ape ancestors to who we are today, that the change was progressive, and that the process continues. All of this is wrong.

  Since the time of Darwin, there has been a running debate among evolutionists, with Darwin himself taking the view that evolution was and is built on gradual transition, shade to new shade, almost imperceptibly between generations. The opposing and minority view through most of this debate has been that evolution makes sudden radical shifts, a view the controversial evolutionary biologists Stephen Jay Gould and Niles Eldredge labeled “punctuated equilibrium.” The consensus now in human evolution is with the latter point—punctuated equilibrium—and we agree.

  In fact, the consensus view says the package we call human, Homo sapiens, emerged as a whole in Africa on the order of a
bout fifty thousand years ago. Not much has happened since. This is Human 1.0 and there have been no significant upgrades.

  The consensus view was laid out by Gould himself: “There’s been no biological change in humans in 40,000 or 50,000 years. Everything we call culture and civilization we’ve built with the same body and brain.”

  Yet embedded in this same cartoon and in popular understanding is a second, wrong idea, the idea of a series of links and missing links. In fact, there was not a neat line of human ancestors, each shading to the next to become more and more humanlike every step of the way. The human family tree is not a towering pine with a dominant central trunk. It is more of a bush than a tree, with a series of side branches and dead ends. The most obvious example of this is the case of the Neanderthal, long known from the fossil record in Europe, Asia, and North Africa. Neanderthals are the knuckle draggers in the middle panels of the cartoon; they’re also a term of insult that we use for fellow humans we consider unrefined or “unevolved,” to cite one of the more egregious readings of the fundamentals of evolution. The assumption in this is clear. Neanderthals were simply a step along the way to the pinnacle, to us.

  But human evolution is not a linear progression. Rather, there evolved and existed for literally millions of years—much longer than we have existed—a handful of species of viable, big-brained, upright, tool-wielding, hunting, social primates, each successful in its own niche and place. Yet modern Homo sapiens appear on the scene only fifty thousand or so years ago, after 90 percent of hominid evolutionary time has already passed, and suddenly we become a breakout species. Suddenly, all of those other perfectly viable hominid species are extinct, every single one. We are the only remaining species in the genus Homo.

  Interestingly enough, there was a corresponding decrease not just in species but in genetic diversity among Homo sapiens. All species of Homo, not just Homo sapiens, trace their lineage to Africa. There is no serious debate or disagreement about this. And there remains in Africa some genetic diversity among Homo sapiens, just as one might expect in a center of origin. But beyond Africa, there is very little genetic variation in humans. There’s a good explanation for this. Separation of populations is the sponsor of diversity and speciation. That is, branches occur in an evolutionary tree when some sort of usual natural event—sea level rise makes an island; glaciers divide a home range—isolates subpopulations and they begin to diverge genetically. But for at least fifty thousand years, all humans have been connected to one another through travel, trade networks, and migration. The result is a genetically homogeneous population. As a practical matter, this means when we speak of human nature, we speak of all humans, both through the time span of fifty thousand years and across the planet. Our long-standing networks of connection mean there is no pressure to drift toward a new species, no pressure to evolve.

  Nonetheless, there is some variation and even innovation. Much is made of these differences among populations for deep-seated reasons having nothing to do with genetics. Take, for instance, the relatively recent experiment in light skin and blond hair. Through most of human history, maybe 80 percent of it, humans were universally dark-skinned. The experiment in light skin began in Europe only about twenty thousand years ago, an adaptation to inhabiting places with little sun. Think of how much we humans make of this tiny and insignificant blip in the total genetic makeup of our species, how much of recent human history hinges on who has it and who doesn’t, “it” being a subtle little tweak not even readable in the collective genome.

  Other recent experiments include such genetic variations as lactose tolerance and resistance to malaria as evidenced in a tropical disposition toward sickle-cell anemia. In this sense, we humans are evolving, but over the course of fifty thousand years, the changes have been so slight as to border on inconsequential. At least by genetic predisposition, we are no taller, no faster or slower, no smarter than were the first Homo sapiens. We are to the core the same guys who somehow outcompeted, outsurvived a handful of very similar upright apes to do something no other species has done before or since: inhabit every square inch of land on our planet.

  But no matter how it happened, it is clear that something unprecedented took place about fifty thousand years ago. This creature called “human” appeared all of a sudden and almost as suddenly was a breakout species. The evolutionary changes that powered this breakout are the core strengths of our species and the very characteristics that we ought to pay attention to. What are these traits?

  BORN TO RUN?

  Start with bipedalism and running. Our habit of walking on two legs is instructive in terms of what we might gain by reexamining the issue with a fresh set of eyes.

  There’s a beat-up pair of Inov-8 running shoes parked under David Carrier’s desk in his office at the University of Utah, and the trained eye can spot these as every bit as telling as the shape of a thigh bone. This brand is British and happens to be favored by a subset of the tribe of minimalist runners who negotiate rough mountain trails. Carrier, a trim, genial middle-aged guy with oval metal-rimmed glasses, a brush of a mustache, and a frizz of curly hair, confirms for a visitor that he is indeed a mountain runner, but this is not his claim to fame, at least in the running world, and his claim to fame in the scientific world is different still. Runners know him as the guy who tried and failed to run an antelope to death in Wyoming but then eventually figured out how to get the job done with instruction from African bushmen. Turns out it wasn’t about running; it was about empathy.

  Carrier’s work and that of his colleagues—his mentor Dennis Bramble, also of the University of Utah, and Daniel Lieberman of Harvard—is significant beyond dead antelope to those of us who run and those of us who should run. Their findings figure front and center in a way-too-common experience: a runner consults a doctor to complain of some injury and then hears the doctor intone the sober advice, “You know, the human body is just not made for running.” Thanks to Carrier’s work, the runner can confidently answer, “Nonsense.” Humans are in fact the best endurance runners on the planet. The best. Might this have something to do with our dominance of the planet, that we are the lone surviving upright ape?

  Much is made of the fact that apes are our closest relatives, that humans are the third species of chimpanzee, and this has produced the related and wrong assumption that humans are simply apes with somehow more refined apelike features, a tweak here, a tweak there—new shades, not new colors. Yet the evidence from endurance running makes a very different case. Humans are a radical departure from chimp design.

  In their pivotal paper about this in the journal Nature, Bramble and Lieberman analyzed the whole issue in terms of running versus walking—a way of challenging the common assumption that humans are built to walk, not run. All apes can run, sort of, but not fast and not far, and certainly not gracefully. Humans can do all of this, and this simple fact can be clearly read in our anatomical structure, in the bones. The research detailed twenty-six adaptations of the human skeleton specific to running, not walking. Some of these are, as you might expect, in the legs and feet. For instance, running requires a springy arched foot, which humans have but no other apes do. Likewise mandatory are our elongated Achilles tendons and long legs relative to the rest of the body. Running, as opposed to walking, requires counterrotation, which is to say that the upper body rotates counter to the lower, negotiated by a pivot of the hips. So running requires a far greater commitment from the upper body than walking does, and a whole collection of features designed to cope with the shifting mass.

  All of these features we share with other running species, even though all of the others are quadrupeds like horses and dogs (and the fact that these two elegant runners are our closest domesticated companions through time ought to serve as a hint to the basis of the relationship). We share none of these characteristics with other species of apes—that is, with the species one limb away on the family tree. To adapt humans to running, evolution reused some older adaptations from unrelated
species, and all of this took place suddenly about two million years ago with the emergence of our genus, hominids. This means that not only are we adapted to run, but running defines us.

  Science has known some of this for a long time, but it was Carrier who demonstrated why this sudden departure from the rest of the ape line was so important. His working hypothesis was something called persistence hunting. True enough, many mammals, especially mammals long recognized as important food sources for humans, are terribly fast runners. Evolution takes care of them as well. But those creatures—usually ungulates like deer and antelope—are sprinters, meaning all flash but no endurance. Carrier believed that if running was so important as to deliver a watershed in evolution, humans must have used the skill to get food, persistently running game animals until they tired and faltered, and then closing in for the kill.