Last Ape Standing: The Seven-Million-Year Story of How and Why We Survived

by Chip Walter

  When you are thinking, and talking, to yourself, the you that you are speaking to is a symbol. Like a reflection in a mirror, it is a representation made possible because your brain can generate symbols. Just as your mind symbolically represents the other people in your life, it also uses this trick to represent a version of you, which makes possible an enormously powerful force in your life, this second you, who is diligently and deeply influencing your every feeling, thought, and choice.

  But to exert this influence, your brain pulls off still another astonishing feat. It changes itself physically. The symbolic “you” alters the real “you.” Study after study has shown that the generation of our own thoughts and memories transforms the chemical and physical structures of our brains, in real time. Mind–boggling as we might find this, we shouldn’t be horribly shocked. If our brains are the prime drivers of our behaviors, then when we think, feel, imagine, or change our minds in any way, our brain must also change. How can it not? Our actions, feelings, and thoughts are simply the dynamic reflections of the brain’s physical, chemical, and electrical states. If you doubt that your brain dictates your reality, just drink a few shots of tequila. Your reality changes because your brain chemistry has been remixed. The same is true, if more subtly, when you whip up your brain chemistry by worrying or recalling a warm memory or losing your temper because that guy in the truck cut you off in traffic this morning.

  In this way the brain changes itself, commands itself, reacts to itself, reshapes itself. It somehow bootstraps self–awareness and self–determination and simultaneously generates a symbolic self to be aware of and to command (as opposed to a god or a demon who dictates orders). This is a little like a box of cake ingredients purposefully opening and mixing themselves, then hopping into an oven to bake. This means that you and me (and every other of the seven billion humans currently alive on planet Earth) are, as Douglas Hofstadter might put it, “a strange loop,” a supreme example of recursion, a matryoshka doll of selves.

  To understand why we have come to operate this way, think of social interaction as a kind of rapidly changing ecosystem made up of a mix of personalities that requires constant adaptation to the shifting agendas, relationships, alliances, and power struggles within the group. In the highly social and very bright species that preceded us, part of the battle for individuals would have been to keep motives and relationships straight in their own minds. Those among our ancestors who could successfully track and recall the behaviors of their friends and enemies would have excelled, survived, and passed their genes along.

  To manage this, they must have learned to symbolize different personalities. Maybe Goog tended to be aggressive; Targ, helpful and friendly; Moop, well organized and smart. This would have helped them “slot” others into organizational categories so they could deal with them in ways they saw fit, depending on their own personalities. Since these relationships only matter in so far as they are connected to you, along the way it would have been impossible not to eventually apply the same index to you. We became to ourselves another person in our social ecology.

  As evolution continually favored smarter and increasingly self–aware creatures from Homo erectus to ergaster to heidelbergensis, Neanderthals, Denisovans, and Homo sapiens eventually emerged. Both we and Neanderthals developed large brains and complex prefrontal cortices, but we developed in different parts of the world, under entirely different circumstances, split from a common ancestor.g We both may have developed spoken language, but very different kinds. We were both self–aware and capable of symbolizing, but to what extent remains unclear. Neanderthals may never have developed a highly complex and fully symbolic inner world, and Homo sapiens may not have pulled off this level of cerebral legerdemain themselves until fifty thousand years ago, maybe later.

  Perhaps then the prefrontal cortex reached a plateau where it could not only fully symbolize others, but manage the one last thing that made us so profoundly different from all other primates and humans that had come before us or even grown up with us: symbolize ourselves. With that, everything changed, radically. Because when we could fully symbolize ourselves, it meant that we could also begin to embed our symbolic selves among all the other symbols around us. We could begin, entirely inside our minds, to imagine what we would do before we did it. We could guide our behaviors, or at least conceive of guiding our behaviors, the way a chess player moves the pieces on a chessboard. By creating a symbol of ourselves, we became conscious and self–aware, capable of purposefully planning our behavior.

  We could imagine.

  That, in itself, represents a remarkable leap, but it made still another leap possible. The moment we consciously act on a scenario that we have imagined, it means we have taken control of our behavior. We have consciously made choices and acted on them. With the invention of a symbolic “you,” intention and free will were born. Or at least the convincing illusions of them.

  So the voice in your head that is talking to you? It’s you. But the person that is listening isn’t, not precisely. It’s a symbol you have created. An image of you, a virtual version, like an avatar in a computer game, except the computer game is your inner mental life, the place where you map your actions and make your choices before transforming them into reality. The “you” you talk to is a simulation.

  Looked at this way, our “selves” are, quite literally, a figment of our imaginations, the ultimate illusion, but an extremely useful one because this illusion has enabled us to take a hand in the control of our fates, at least more than any other creature ever has. We are not only an animal that can explore a life not yet lived, and dream of a future we desire, we can also take hold of those dreams and make them come true. Out of a chaotic flux of random events in nature that have no agenda and are utterly incapable of making any plans, we have evolved into a planning, agenda–making, dream–conjuring creature. We are the first survival machines to also become living, breathing imagination machines.

  If you compare us with other animals, our ability to create symbols turns out to be a kind of superpower, like being able to fly or peer through rock with X-ray eyes. They are super because they have transformed us into a world–changing, supremely adaptable, überbeing. Not simply “a figure in the landscape,” as Jacob Bronowski put it, “but the shaper of the landscape … the ubiquitous animal.” This isn’t human arrogance speaking, declaring that the greatest advance in all of evolution has been the sudden emergence of our kind. This takes nothing away from the remarkable abilities of other animals. It simply states an irresistible fact, as sure as blue whales are gargantuan, cheetahs are swift, and grunion dance on the beach under full moons; we alone have developed this superpower that lets us make symbols, and that has made us, bar none, the most adaptable creature planet Earth has yet witnessed.

  The strange thing is, this virtual version, this symbol of our “selves,” not only reflects on itself (and selves within selves like the reflections of two facing mirrors), but also reflects on the mind that makes it possible in the first place. That can sometimes make our mental lives even more complicated than they already are. Superpowers, it seems, often bring difficult trade–offs in tow. Like mental illness, for example.

  When I was a child, I once asked my mother why our new Chrysler New Yorker didn’t have power windows, when they were all the rage in the newest cars. “The more fancy the gadgets,” she answered, “the more there is to break down. We would only have to fix it later.” The makers of intricate technologies like cars, computers, and spaceships have inevitably found that when the engineering of anything reaches a certain level of complexity, it is much more difficult to maintain than simpler systems. A straw rarely breaks down. Nor do paperweights, generally. Space shuttles, on the other hand, were designed with thousands of “redundant systems” because so many functions could go haywire. Yet when it comes to complexity, a shuttle holds not even the dimmest candle to the human brain. The brains you and I carry into adulthood have an estimated 100,000,000,000 (one hund
red billion) neurons, each connected to as many as a thousand other neurons. This is sophistication of the incomprehensible variety. The human brain is so convoluted in its wiring, genetics, and neurochemistry that it is a wonder that so many of them function so well. Of course those that evolved and didn’t work up to snuff quickly resulted in the death of their owner and were swiftly tossed from the gene pool. Still the modern human brain will, and does, often go sideways. We see it in the number of people who suffer from chronic depression, not to mention more dramatic and damaging conditions such as bipolar disorder, schizophrenia, autism, obsession, compulsion, attention deficit, and multiple personality disorder. And that’s just some of the labels we use to describe mental illness. The more we come to understand the human brain, the more we discover what can go wrong with it. Arguably, no human brain is really “normal.”

  Mental illnesses like these are uniquely human because they are linked to uniquely human capabilities like language, symbolization, and working memory. Neurologists and psychologists have been especially curious about two mental illnesses—schizophrenia and autism—and what each has to say about the way we evolved.

  Schizophrenia is a mental disorder characterized by trouble differentiating between reality and imaginary worlds and experiences. Schizophrenics can suffer from extreme paranoia, delusions, disorganized speech and thinking. In severe cases they often hear voices and many times carry on conversations with the voices because to them they aren’t the voice most of us identify as our “self,” but belong to someone else, usually unseen. This is something like Julian Jaynes’s bicameral mind. Those who speak are distinct, often conflicting, even abusive, and it can be maddening, or, occasionally, captivating. One schizophrenic reported waking up to hear two Israeli generals debating battle strategy, a subject he had never before in his life contemplated. “It was a fascinating experience,” he recalled. It’s an insight into the power of the human brain that someone can have that much detailed knowledge about a subject as arcane and complex as military strategy, yet not consciously realize it. It makes you wonder what treasures of information lie untapped within each of our minds.2

  Schizophrenics suffering from acute paranoia often convince themselves that they are being hunted or persecuted. These fears can become part of an elaborate imaginary world they live in, a world that is as absolutely real to them as our daily lives are to the rest of us. The richness of these worlds and scenarios are further testaments to the power of human creativity. We on the outside see this as madness, and it is excruciating for those who suffer through such horrible conflicts and feelings, but it is possible to see how our minds can go to places like these. After all, don’t each of us hear a voice that often sends us conflicting messages? The only difference is that we identify that voice as our own, not as belonging to unexpected, intruding, and ethereal companions who pop into our consciousness unbidden and unannounced.

  And don’t we all live in imaginary worlds of our own making—in the tomorrows that we plan; the lives that we lay out; the conversations we imagine having with friends or enemies? Every piece of fiction ever written is an elaborate imagining manufactured out of the symbols in the mind of its author, no less labyrinthine in its way than the delusions of schizophrenia. The line between normalcy and madness may be finer than any of us would like to believe.

  Autism is not usually as dramatic or debilitating as schizophrenia can be, but it, too, provides a glimpse into the mysteries of the creative spirit. Like schizophrenia, autism runs along a spectrum from mild to severe, and some of the underlying symptoms for it are similar: difficulty socializing with others, a tendency to become obsessed with specific behaviors, sometimes self–injury or the need for repetitive rituals that might involve entertainment, food, or dress. In about one case out of ten, autistic people develop remarkable talents, but are otherwise incapable of leading what the rest of us might consider a normal life. Researchers sometimes refer to them as autistic savants. The movie Rain Man was based on real–life autistic Bill Sackter and another savant, Kim Peek, who, for reasons not entirely clear, was blessed with an astounding memory, yet struggled with some of life’s most basic undertakings. Sackter passed away in 1983, and Peek died of a heart attack in 2009, but both were remarkable people. Sackter was also a model for Charlie Gordon in the novel Flowers for Algernon and the movie it inspired about a mentally retarded man who becomes a genius before returning to his earlier state. Peek could read thousands of pages of facts and trivia, then much later recall with almost perfect accuracy the information on those pages, say, the weather on December 14, 1964, or Roberto Clemente’s batting average in 1967.

  Other autistic savants have been genetically bestowed with extraordinary talents as musicians, painters, mathematicians, sculptors, even writers. Sometimes the talents are wide–ranging and accompanied by high intelligence, as in the case of Matt Savage, who at age six taught himself to read piano music and went on to study both jazz and classical piano at the New England Conservatory of Music. In between he also somehow found time to win a statewide geography bee, compose many of his own pieces, and release nine albums while touring the world and appearing with an impressive list of jazz greats.

  Alonzo Clemons on the other hand has an IQ of 50, the result of a severe brain injury as a child. Strangely, though, Alonzo developed a talent for creating marvelously accurate animal sculptures out of clay, even if he had only caught a glimpse of the animal or seen a photo or drawing of it in two dimensions. His works have sold for tens of thousands of dollars. When looking at Clemons’s works, it’s difficult not to think of the fluid, breathtaking artwork in the caves of Altamira and Lascaux. Were these the works of a Cro–Magnon savant, someone seemingly endowed with magical talents, and magical ways of representing the world?

  Seth F. Henriett is another savant blessed with a high IQ like Matthew Savage, and a marvelously broad array of talents. Though Henriett suffered from severe social problems and autoimmune disorders early in her life, she also revealed aptitudes for music and art. She played flute at the age of seven and contrabass at the age of eleven. By age thirteen her abstract and surrealistic paintings were gaining attention. Shortly afterward she wrote two books about her experience as an autistic and won several international writing competitions with her stories, essays, and poems.

  Despite these staggering skills, each of these people has difficulty relating to others. They shun making eye contact or being touched; they often prefer to be alone and struggle with even basic personal interaction. Yet don’t all of us exhibit a quirk or two, or three? Phobias, preferences, habits, interests, even obsessions? Various experts have speculated that some well–known people in history were autistic to some extent, or another, including Lewis Carroll, Charles Darwin, Emily Dickinson, Thomas Jefferson, Isaac Newton, and Wolfgang Mozart. How much emptier would human civilization be had it been bereft of the genius of these minds?

  On the other hand, 90 percent of autistics do not become savants, though a significant number are highly functional. Again the affliction is not binary, one or the other, all on or all off. You and I might have smidgens of autism and not realize it, especially if you happen to be a man. Scientists have sometimes described autism as an extreme version of the male brain. And in truth, of all the world’s autistics, only one fifth are female.3 This may be because women have more axons and dendrites, which are the pathways in the brain that enable it to work as a unit. Men’s brains have more neurons. In effect, this makes male brains less networked than women’s, but outfitted with more processing power, largely focused, it seems, on spatial and temporal capabilities. This doesn’t make one sex smarter or more talented than the other, simply different. It also helps explain, at least according to some scientists, why men are sometimes less socially tuned in than females, and why women are superior, generally, at reading social cues.

  The issue with autistics isn’t so much with the number or the function of their neurons, but that they suffer from a dearth of connecti
ons between them. What would cause this scarcity? Neoteny, or more accurately the processes that make neoteny possible.

  Remember, complexity creates more opportunity for something to go wrong. During the crucial first three years that follow birth, when the brain triples in size and personal experience so strongly shapes the billions of pathways between neurons in the brain, cerebral development may mysteriously go awry in people who grow up autistic. Connections may be delayed, accelerated, or stunted. Studies show that different sectors of the brain develop in ways that keep them more separated from one another than normal, like islands in a sea, out of touch and segregated. Yet, some modules may become overwired, which could help explain remarkable feats of memory, mathematics, music, or art and views of the world so different from those of the rest of us.

  The downside, of course, is that the segregations also make it more difficult to be socially sensitive and tuned in to other people’s nonverbal communications—their smiles, tones of voice, body language—the little things we unconsciously and effortlessly do that grease the skids of human relationships. These create a deficit of a Theory of Mind, a brain largely incapable of symbolizing its owner as a self to itself, let alone symbolize others. Rather than symbolization going rampant and boisterous as it does in schizophrenia, in autism it is reduced, stunted, and balkanized, with the manifold human genius for socialization sometimes being abandoned in exchange for a single, condensed, but breathtaking talent.

  Why, if evolution so ruthlessly discards traits and behaviors that undercut a living thing’s ability to survive and mate, have mental illnesses like these and others survived? Can they serve a purpose? Or did they once? In a study published in Nature in 2007 researchers led by Bernard Crespi and Steve Dorus analyzed human DNA from populations around the world as well as primate genomes dating back to the shared ancestor of both humans and chimpanzees to get a handle on what genes led to schizophrenia, why they evolved, and why the illness is still among us. They were astonished to find that of seventy–six gene variations known to be strongly related to schizophrenia, twenty-eight showed sturdy evidence that they were favored by natural selection when compared with other genes, even those associated with the most severe forms of schizophrenia. In other words, the genes weren’t randomly repeated accidents; the forces of evolution were actively selecting them and passing them on. Why?