But these robots are trained by conscious minds. An aspiring tennis player does not have to know anything about building robotics (that was taken care of by evolution). Rather, the challenge is to program the robotics. In this case, the challenge is to program the machinery to devote its flexible computational resources to rapidly and accurately volleying a fuzzy yellow ball over a short net.
And this is where consciousness plays a role. Conscious parts of the brain train other parts of the neural machinery, establishing the goals and allocating the resources. “Grip the racket lower when you swing,” the coach says, and the young player mumbles that to herself. She practices her swing over and over, thousands of times, each time setting as her end point the goal of smashing the ball directly into the other quadrant. As she serves again and again, the robotic system makes tiny adjustments across a network of innumerable synaptic connections. Her coach gives feedback which she needs to hear and understand consciously. And she continually incorporates the instructions (“Straighten your wrist. Step into the swing.”) into the training of the robot until the movements become so ingrained as to no longer be accessible.
Consciousness is the long-term planner, the CEO of the company, while most of the day-to-day operations are run by all those parts of her brain to which she has no access. Imagine a CEO who has inherited a giant blue-chip company: he has some influence, but he is also coming into a situation that has already been evolving for a long time before he got there. His job is to define a vision and make long-term plans for the company, insofar as the technology of the company is able to support his policies. This is what consciousness does: it sets the goals, and the rest of the system learns how to meet them.
You may not be a professional tennis player, but you’ve been through this process if you ever learned to ride a bicycle. The first time you got on, you wobbled and crashed and tried desperately to figure it out. Your conscious mind was heavily involved. Eventually, after an adult guided the bicycle along, you became able to ride on your own. After some time, the skill became like a reflex. It became automatized. It became just like reading and speaking your language, or tying your shoes, or recognizing your father’s walk. The details became no longer conscious and no longer accessible.
One of the most impressive features of brains—and especially human brains—is the flexibility to learn almost any kind of task that comes its way. Give an apprentice the desire to impress his master in a chicken-sexing task, and his brain devotes its massive resources to distinguishing males from females. Give an unemployed aviation enthusiast a chance to be a national hero, and his brain learns to distinguish enemy aircraft from local flyboys. This flexibility of learning accounts for a large part of what we consider human intelligence. While many animals are properly called intelligent, humans distinguish themselves in that they are so flexibly intelligent, fashioning their neural circuits to match the tasks at hand. It is for this reason that we can colonize every region on the planet, learn the local language we’re born into, and master skills as diverse as playing the violin, high-jumping and operating space shuttle cockpits.
MANTRA OF THE FAST AND EFFICIENT BRAIN: BURN JOBS INTO THE CIRCUITRY
When the brain finds a task it needs to solve, it rewires its own circuitry until it can accomplish the task with maximum efficiency.26 The task becomes burned into the machinery. This clever tactic accomplishes two things of chief importance for survival.
The first is speed. Automatization permits fast decision making. Only when the slow system of consciousness is pushed to the back of the queue can rapid programs do their work. Should I swing forehand or backhand at the approaching tennis ball? With a ninety-mile-per-hour projectile on its way, one does not want to cognitively slog through the different options. A common misconception is that professional athletes can see the court in “slow motion,” as suggested by their rapid and smooth decision making. But automatization simply allows the athletes to anticipate relevant events and proficiently decide what to do. Think about the first time you tried a new sport. More-experienced players defeated you with the most elementary moves because you were struggling with a barrage of new information—legs and arms and jumping bodies. With experience, you learned which twitches and feints were the important ones. With time and automatization, you achieved speed both in deciding and in acting.
The second reason to burn tasks into the circuitry is energy efficiency. By optimizing its machinery, the brain minimizes the energy required to solve problems. Because we are mobile creatures that run on batteries, energy saving is of the highest importance.27 In his book Your Brain Is (Almost) Perfect, neuroscientist Read Montague highlights the impressive energy efficiency of the brain, comparing chess champion Garry Kasparov’s energy usage of about 20 watts to the consumption of his computerized competitor Deep Blue, in the range of thousands of watts. Montague points out that Kasparov played the game at normal body temperature, while Deep Blue was burning hot to the touch and required a large collection of fans to dissipate the heat. Human brains run with superlative efficiency.
Kasparov’s brain is so low-powered because Kasparov has spent a lifetime burning chess strategies into economical rote algorithms. When he started playing chess as a boy, he had to walk himself through cognitive strategies about what to do next—but these were highly inefficient, like the moves of an overthinking, second-guessing tennis player. As Kasparov improved, he no longer had to consciously walk through the unfolding steps of a game: he could perceive the chess board rapidly, efficiently, and with less conscious interference.
In one study on efficiency, researchers used brain imaging while people learned how to play the video game Tetris. The subjects’ brains were highly active, burning energy at a massive scale while the neural networks searched for the underlying structures and strategies of the game. By the time the subjects became experts at the game, after a week or so, their brains consumed very little energy while playing. It’s not that the player became better despite the brain being quieter; the player became better because the brain was quieter. In these players, the skills of Tetris has been burned down into the circuitry of the system, such that there were now specialized and efficient programs to deal with it.
As an analogy, imagine a warring society that suddenly finds itself with no more battles to wage. Its soldiers decide to turn to agriculture. At first they use their battle swords to dig little holes for seeds—a workable but massively inefficient approach. After a time, they beat their swords into plowshares. They optimize their machinery to meet the task demands. Just like the brain, they’ve modified what they have to address the task at hand.
This trick of burning tasks into the circuitry is fundamental to how brains operate: they change the circuit board of their machinery to mold themselves to their mission. This allows a difficult task that could be accomplished only clumsily to be achieved with rapidity and efficiency. In the logic of the brain, if you don’t have the right tool for the job, create it.
* * *
So far we’ve learned that consciousness tends to interfere with most tasks (remember the unhappy centipede in the ditch)—but it can be helpful when setting goals and training the robot. Evolutionary selection has presumably tuned the exact amount of access the conscious mind has: too little, and the company has no direction; too much, and the system gets bogged down solving problems in a slow, clunky, energy-inefficient manner.
When athletes make mistakes, coaches typically yell, “Think out there!” The irony is that a professional athlete’s goal is to not think. The goal is to invest thousands of hours of training so that in the heat of the battle the right maneuvers will come automatically, with no interference from consciousness. The skills need to be pushed down into the players’ circuitry. When athletes “get into the zone,” their well-trained unconscious machinery runs the show, rapidly and efficiently. Imagine a basketball player standing at the free-throw line. The crowd yells and stomps to distract him. If he’s running on conscious machinery,
he’s certain to miss. Only by relying on the overtrained, robotic machinery can he hope to drain the ball through the basket.28
Now you can leverage the knowledge gained in this chapter to always win at tennis. When you are losing, simply ask your opponent how she serves the ball so well. Once she contemplates the mechanics of her serve and tries to explain it, she’s sunk.
We have learned that the more things get automatized, the less conscious access we have. But we’re just getting started. In the next chapter we’ll see how information can get buried even deeper.
*It is currently an open question whether courts of law will allow these tests to be admitted as evidence—for example, to probe whether an employer (or attacker or murderer) shows signs of racism. At the moment it is probably best if these tests remain outside the courtroom, for while complicated human decisions are biased by inaccessible associations, it is difficult to know how much these biases influence our final behavior. For example, someone may override their racist biases by more socialized decision-making mechanisms. It is also the case that someone may be a virulent racist, but that was not their reason for a particular crime.
The Kinds of Thoughts That Are Thinkable
“Man is a plant which bears thoughts, just as a rose-tree bears roses and an apple-tree bears apples.”
—Antoine Fabre D’Olivet,
L’Histoire philosophique du genre humain
Spend a moment thinking about the most beautiful person you know. It would seem impossible for eyes to gaze upon this person and not be intoxicated with attraction. But everything depends on the evolutionary program those eyes are connected to. If the eyes belong to a frog, this person can stand in front of it all day—even naked—and will attract no attention, perhaps only a bit of suspicion. And the lack of interest is mutual: humans are attracted to humans, frogs to frogs.
Nothing seems more natural than desire, but the first thing to notice is that we’re wired only for species-appropriate desire. This underscores a simple but crucial point: the brain’s circuits are designed to generate behavior that is appropriate to our survival. Apples and eggs and potatoes taste good to us not because the shapes of their molecules are inherently wonderful, but because they’re perfect little packages of sugars and proteins: energy dollars you can store in your bank. Because those foods are useful, we are engineered to find them tasty. Because fecal matter contains harmful microbes, we have developed a hardwired aversion to eating it. Note that baby koalas—known as joeys—eat their mother’s fecal matter to obtain the right bacteria for their digestive systems. These bacteria are necessary for the joeys to survive on otherwise-poisonous eucalyptus leaves. If I had to guess, I’d say that fecal matter tastes as delicious to the joey as an apple does to you. Nothing is inherently tasty or repulsive—it depends on your needs. Deliciousness is simply an index of usefulness.
Many people are already familiar with these concepts of attraction or tastiness, but it is often difficult to appreciate how deep this evolutionary carving goes. It’s not simply that you are attracted to humans over frogs or that you like apples more than fecal matter—these same principles of hardwired thought guidance apply to all of your deeply held beliefs about logic, economics, ethics, emotions, beauty, social interactions, love, and the rest of your vast mental landscape. Our evolutionary goals navigate and structure our thoughts. Chew on that for a moment. It means there are certain kinds of thoughts we can think, and whole categories of thoughts we cannot. Let’s begin with all the thoughts you didn’t even know you were missing.
THE UMWELT: LIFE ON THE THIN SLICE
“Incredible the Lodging
But limited the Guest.”
—Emily Dickinson
In 1670, Blaise Pascal noted with awe that “man is equally incapable of seeing the nothingness from which he emerges and the infinity in which he is engulfed.”1 Pascal recognized that we spend our lives on a thin slice between the unimaginably small scales of the atoms that compose us and the infinitely large scales of galaxies.
But Pascal didn’t know the half of it. Forget atoms and galaxies—we can’t even see most of the action at our own spatial scales. Take what we call visible light. We have specialized receptors in the backs of our eyes that are optimized for capturing the electromagnetic radiation that bounces off objects. When these receptors catch some radiation, they launch a salvo of signals into the brain. But we do not perceive the entire electromagnetic spectrum, only a part of it. The part of the light spectrum that is visible to us is less than a ten-trillionth of it. The rest of the spectrum––carrying TV shows, radio signals, microwaves, X-rays, gamma rays, cell phone conversations, and so on––flows through us with no awareness on our part.2 CNN news is passing through your body right now and you are utterly blind to it, because you have no specialized receptors for that part of the spectrum. Honeybees, by contrast, include information carried on ultraviolet wavelengths in their reality, and rattlesnakes include infrared in their view of the world. Machines in the hospital see the X-ray range, and machines in the dashboard of your car see the radio frequency range. But you can’t sense any of these. Even though it’s the same “stuff”—electromagnetic radiation—you don’t come equipped with the proper sensors. No matter how hard you try, you’re not going to pick up signals in the rest of the range.
What you are able to experience is completely limited by your biology. This differs from the commonsense view that our eyes, ears, and fingers passively receive an objective physical world outside of ourselves. As science marches forward with machines that can see what we can’t, it has become clear that our brains sample just a small bit of the surrounding physical world. In 1909, the Baltic German biologist Jakob von Uexküll began to notice that different animals in the same ecosystem pick up on different signals from their environment.3 In the blind and deaf world of the tick, the important signals are temperature and the odor of butyric acid. For the black ghost knifefish, it’s electrical fields. For the echolocating bat, air-compression waves. So von Uexküll introduced a new concept: the part that you are able to see is known as the umwelt (the environment, or surrounding world), and the bigger reality (if there is such a thing) is known as the umgebung.
Each organism has its own umwelt, which it presumably assumes to be the entire objective reality “out there.” Why would we ever stop to think that there is more beyond what we can sense? In the movie The Truman Show, the eponymous Truman lives in a world completely constructed around him (often on the fly) by an intrepid television producer. At one point an interviewer asks the producer, “Why do you think Truman has never come close to discovering the true nature of his world?” The producer replies, “We accept the reality of the world with which we’re presented.” He hit the nail on the head. We accept the umwelt and stop there.
Ask yourself what it would be like to have been blind from birth. Really think about this for a moment. If your guess is “it would something like blackness” or “something like a dark hole where vision should be,” you’re wrong. To understand why, imagine you’re a scent dog such as a bloodhound. Your long nose houses two hundred million scent receptors. On the outside, your wet nostrils attract and trap scent molecules. The slits at the corners of each nostril flare out to allow more air flow as you sniff. Even your floppy ears drag along the ground and kick up scent molecules. Your world is all about smelling. One afternoon, as you’re following your master, you stop in your tracks with a revelation. What is it like to have the pitiful, impoverished nose of a human being? What can humans possibly detect when they take in a feeble little noseful of air? Do they suffer a blackness? A hole of smell where smell is supposed to be?
Because you’re a human, you know the answer is no. There is no hole or blackness or missing feeling where the scent is absent. You accept your reality as it’s presented to you. Because you don’t have the smelling capabilities of a bloodhound, it doesn’t even strike you that things could be different. The same goes for people with color blindness: unt
il they learn that others can see hues they cannot, the thought does not even hit their radar screen.
If you are not color-blind, you may well find it difficult to imagine yourself as color-blind. But recall what we learned earlier: that some people see more colors than you do. A fraction of women have not just three but four types of color photoreceptors—and as a result they can distinguish colors that the majority of humankind will never differentiate.4 If you are not a member of that small female population, then you have just discovered something about your own impoverishments that you were unaware of. You may not have thought of yourself as color-blind, but to those ladies supersensitive to hues, you are. In the end, it does not ruin your day; instead, it only makes you wonder how someone else can see the world so strangely.
And so it goes for the congenitally blind. They are not missing anything; they do not see blackness where vision is missing. Vision was never part of their reality in the first place, and they miss it only as much as you miss the extra scents of the bloodhound dog or the extra colors of the tetrachromatic women.