Читать книгу Stumbling on Happiness - Daniel Gilbert - Страница 5

PRIESTS VOW TO REMAIN CELIBATE, physicians vow to do no harm and letter carriers vow to swiftly complete their appointed rounds despite snow, sleet and split infinitives. Few people realize that psychologists also take a vow, promising that at some point in their professional lives they will publish a book, a chapter or at least an article that contains this sentence: ‘The human being is the only animal that…’ We are allowed to finish the sentence any way we like, but it has to start with those eight words. Most of us wait until relatively late in our careers to fulfil this solemn obligation because we know that successive generations of psychologists will ignore all the other words that we managed to pack into a lifetime of well-intentioned scholarship and remember us mainly for how we finished The Sentence. We also know that the worse we do, the better we will be remembered. For instance, those psychologists who finished The Sentence with ‘can use language’ were particularly well remembered when chimpanzees were taught to communicate with hand signs. And when researchers discovered that chimps in the wild use sticks to extract tasty termites from their mounds (and to bash one another over the head now and then), the world suddenly remembered the full name and mailing address of every psychologist who had ever finished The Sentence with ‘uses tools’. So it is for good reason that most psychologists put off completing The Sentence for as long as they can, hoping that if they wait long enough, they just might die in time to avoid being publicly humiliated by a monkey.

I have never before written The Sentence, but I’d like to do so now, with you as my witness. The human being is the only animal that thinks about the future. Now, let me say up front that I’ve had cats, I’ve had dogs, I’ve had gerbils, mice, goldfish and crabs (no, not that kind), and I do recognize that nonhuman animals often act as though they have the capacity to think about the future. But as bald men with cheap hairpieces always seem to forget, acting as though you have something and actually having it are not the same thing, and anyone who looks closely can tell the difference. For example, I live in an urban neighbourhood, and every autumn the squirrels in my yard (which is approximately the size of two squirrels) act as though they know that they will be unable to eat later unless they bury some food now. My city has a relatively well-educated citizenry, but as far as anyone can tell its squirrels are not particularly distinguished. Rather, they have regular squirrel brains that run food-burying programs when the amount of sunlight that enters their regular squirrel eyes decreases by a critical amount. Shortened days trigger burying behaviour with no intervening contemplation of tomorrow, and the squirrel that stashes a nut in my yard ‘knows’ about the future in approximately the same way that a falling rock ‘knows’ about the law of gravity–which is to say, not really. Until a chimp weeps at the thought of growing old alone, or smiles as it contemplates its summer holiday, or turns down a toffee apple because it already looks too fat in shorts, I will stand by my version of The Sentence. We think about the future in a way that no other animal can, does or ever has, and this simple, ubiquitous, ordinary act is a defining feature of our humanity.[2]

The Joy of Next

If you were asked to name the human brain’s greatest achievement, you might think first of the impressive artefacts it has produced–the Great Pyramid of Giza, the International Space Station or perhaps the Golden Gate Bridge. These are great achievements indeed, and our brains deserve their very own ticker-tape parade for producing them. But they are not the greatest. A sophisticated machine could design and build any one of these things because designing and building require knowledge, logic and patience, of which sophisticated machines have plenty. In fact, there’s really only one achievement so remarkable that even the most sophisticated machine cannot pretend to have accomplished it, and that achievement is conscious experience. Seeing the Great Pyramid or remembering the Golden Gate or imagining the Space Station are far more remarkable acts than is building any one of them. What’s more, one of these remarkable acts is even more remarkable than the others. To see is to experience the world as it is, to remember is to experience the world as it was, but to imagine–ah, to imagine is to experience the world as it isn’t and has never been, but as it might be. The greatest achievement of the human brain is its ability to imagine objects and episodes that do not exist in the realm of the real, and it is this ability that allows us to think about the future. As one philosopher noted, the human brain is an ‘anticipation machine’, and ‘making future’ is the most important thing it does.[3]

But what exactly does ‘making future’ mean? There are at least two ways in which brains might be said to make future, one of which we share with many other animals, the other of which we share with none. All brains–human brains, chimpanzee brains, even ordinary food-burying squirrel brains–make predictions about the immediate, local, personal future. They do this by using information about current events (‘I smell something’) and past events (‘Last time I smelled this smell, a big thing tried to eat me’) to anticipate the event that is most likely to happen to them next (‘A big thing is about to–’).[4] But notice two features of this so-called prediction. First, despite the comic quips inside the parentheses, predictions such as these do not require the brain making them to have anything even remotely resembling a conscious thought. Just as an abacus can put two and two together to produce four without having thoughts about arithmetic, so brains can add past to present to make future without ever thinking about any of them. In fact, it doesn’t even require a brain to make predictions such as these. With just a little bit of training, the giant sea slug known as Aplysia parvula can learn to predict and avoid an electric shock to its gill, and as anyone with a scalpel can easily demonstrate, sea slugs are inarguably brainless. Computers are also brainless, but they use precisely the same trick the sea slug does when they turn down your credit card because you were trying to buy dinner in Paris after buying lunch in LA. In short, machines and invertebrates prove that it doesn’t take a smart, self-aware, conscious brain to make simple predictions about the future.

The second thing to notice is that predictions such as these are not particularly far-reaching. They are not predictions in the same sense that we might predict the annual rate of inflation, the intellectual impact of postmodernism, the heat death of the universe, or Madonna’s next hair colour. Rather, these are predictions about what will happen in precisely this spot, precisely next, to precisely me, and we call them predictions only because there is no better word for them in the English language. But the use of that term—with its inescapable connotations of calculated, thoughtful reflection about events that may occur anywhere, to anyone, at any time–risks obscuring the fact that brains are continuously making predictions about the immediate, local, personal future of their owners without their owners’ awareness. Rather than saying that such brains are predicting let’s say that they are nexting.

Yours is nexting right now. For example, at this moment you may be consciously thinking about the sentence you just read, or about the key ring in your pocket that is jammed uncomfortably against your thigh, or about whether the War of 1812 really deserves its own overture. Whatever you are thinking, your thoughts are surely about something other than the word with which this sentence will end. But even as you hear these very words echoing in your very head, and think whatever thoughts they inspire, your brain is using the word it is reading right now and the words it read just before to make a reasonable guess about the identity of the word it will read next which is what allows you to read so fluently.[5] Any brain that has been raised on a steady diet of film noir and cheap detective novels fully expects the word night to follow the phrase It was a dark and stormy and thus when it does encounter the word night it is especially well prepared to digest it. As long as your brain’s guess about the next word turns out to be right, you cruise along happily, left to right, left to right, turning black squiggles into ideas, scenes, characters and concepts, blissfully unaware that your nexting brain is predicting the future of the sentence at a fantastic rate. It is only when your brain predicts badly that you suddenly feel avocado.

That is, surprised. See?

Now, consider the meaning of that brief moment of surprise. Surprise is an emotion we feel when we encounter the unexpected–for example, thirty-four acquaintances in paper hats standing in our living room yelling ‘Happy birthday!’ as we walk through the front door with a bag of groceries and a full bladder–and thus the occurrence of surprise reveals the nature of our expectations. The surprise you felt at the end of the last paragraph reveals that as you were reading the phrase it is only when your brain predicts badly that you suddenly feel…, your brain was simultaneously making a reasonable prediction about what would happen next. It predicted that sometime in the next few milliseconds your eyes would come across a set of black squiggles that encoded an English word that described a feeling, such as sad or nauseous or even surprised. Instead, it encountered a fruit, which woke you from your dogmatic slumbers and revealed the nature of your expectations to anyone who was watching. Surprise tells us that we were expecting something other than what we got, even when we didn’t know we were expecting anything at all.

Because feelings of surprise are generally accompanied by reactions that can be observed and measured–such as eyebrow arching, eye widening, jaw dropping, and noises followed by a series of exclamation marks–psychologists can use surprise to tell them when a brain is nexting. For example, when monkeys see a researcher drop a ball down one of several chutes, they quickly look to the bottom of that chute and wait for the ball to reemerge. When some experimental trickery causes the ball to emerge from a different chute than the one in which it was deposited, the monkeys display surprise, presumably because their brains were nexting.[6] Human babies have similar responses to weird physics. For example, when babies are shown a video of a big red block smashing into a little yellow block, they react with indifference when the little yellow block instantly goes careening off the screen. But when the little yellow block hesitates for just a moment or two before careening away, babies stare like bystanders at a train wreck–as though the delayed careening had violated some prediction made by their nexting brains.[7] Studies such as these tell us that monkey brains ‘know’ about gravity (objects fall down, not sideways) and that baby human brains ‘know’ about kinetics (moving objects transfer energy to stationary objects at precisely the moment they contact them and not a few seconds later). But more important, they tell us that monkey brains and baby human brains add what they already know (the past) to what they currently see (the present) to predict what will happen next (the future). When the actual next thing is different from the predicted next thing, monkeys and babies experience surprise.

Our brains were made for nexting, and that’s just what they’ll do. When we take a stroll on the beach, our brains predict how stable the sand will be when our foot hits it, and then adjust the tension in our knee accordingly. When we leap to catch a Frisbee, our brains predict where the disc will be when we cross its flight path, and then bring our hands to precisely that point. When we see a sand crab scurry behind a bit of driftwood on its way to the water, our brains predict when and where the critter will reappear, and then direct our eyes to the precise point of its reemergence. These predictions are remarkable in both the speed and accuracy with which they are made, and it is difficult to imagine what our lives would be like if our brains quit making them, leaving us completely ‘in the moment’ and unable to take our next step. But while these automatic, continuous, nonconscious predictions of the immediate, local, personal future are both amazing and ubiquitous, they are not the sorts of predictions that got our species out of the trees and into dress slacks. In fact, these are the kinds of predictions that frogs make without ever leaving their lily pads, and hence not the sort that The Sentence was meant to describe. No, the variety of future that we human beings manufacture–and that only we manufacture–is of another sort entirely.

The Ape That Looked Forward

Adults love to ask children idiotic questions so that we can chuckle when they give us idiotic answers. One particularly idiotic question we like to ask children is this: ‘What do you want to be when you grow up?’ Small children look appropriately puzzled, worried perhaps that our question implies they are at some risk of growing down. If they answer at all, they generally come up with things like ‘the candy guy’ or ‘a tree climber’. We chuckle because the odds that the child will ever become the candy guy or a tree climber are vanishingly small, and they are vanishingly small because these are not the sorts of things that most children will want to be once they are old enough to ask idiotic questions themselves. But notice that while these are the wrong answers to our question, they are the right answers to another question, namely, ‘What do you want to be now?’ Small children cannot say what they want to be later because they don’t really understand what later means.[8] So, like shrewd politicians, they ignore the question they are asked and answer the question they can. Adults do much better, of course. When a thirtyish Manhattanite is asked where she thinks she might retire, she mentions Miami, Phoenix or some other hotbed of social rest. She may love her gritty urban existence right now, but she can imagine that in a few decades she will value bingo and prompt medical attention more than art museums and squeegee men. Unlike the child who can only think about how things are, the adult is able to think about how things will be. At some point between our high chairs and our rocking chairs, we learn about later.[9]

Later! What an astonishing idea. What a powerful concept. What a fabulous discovery. How did human beings ever learn to preview in their imaginations chains of events that had not yet come to pass? What prehistoric genius first realized that he could escape today by closing his eyes and silently transporting himself into tomorrow? Unfortunately, even big ideas leave no fossils for carbon dating, and thus the natural history of later is lost to us forever. But paleontologists and neuroanatomists assure us that this pivotal moment in the drama of human evolution happened sometime within the last 3 million years, and that it happened quite suddenly. The first brains appeared on earth about 500 million years ago, spent a leisurely 430 million years or so evolving into the brains of the earliest primates, and another 70 million years or so evolving into the brains of the first protohumans. Then something happened–no one knows quite what, but speculation runs from the weather turning chilly to the invention of cooking–and the soon-to-be-human brain experienced an unprecedented growth spurt that more than doubled its mass in a little over two million years, transforming it from the one-and-a-quarter-pound brain of Homo habilis to the nearly three-pound brain of Homo sapiens.[10]

Now, if you were put on a hot-fudge diet and managed to double your mass in a very short time, we would not expect all of your various body parts to share equally in the gain. Your belly and buttocks would probably be the major recipients of newly acquired flab, while your tongue and toes would remain relatively svelte and unaffected. Similarly, the dramatic increase in the size of the human brain did not democratically double the mass of every part so that modern people ended up with new brains that were structurally identical to the old ones, only bigger. Rather, a disproportionate share of the growth centred on a particular part of the brain known as the frontal lobe, which, as its name implies, sits at the front of the head, squarely above the eyes (see figure 2). The low, sloping brows of our earliest ancestors were pushed forward to become the sharp, vertical brows that keep our hats on, and the change in the structure of our heads occurred primarily to accommodate this sudden change in the size of our brains. What did this new bit of cerebral apparatus do to justify an architectural overhaul of the human skull? What is it about this particular part that made nature so anxious for each of us to have a big one? Just what good is a frontal lobe?

Fig. 2. The frontal lobe is the recent addition to the human brain that allows us to imagine the future.

Until fairly recently, scientists thought it was not much good at all, because people whose frontal lobes were damaged seemed to do pretty well without them. Phineas Gage was a foreman for the Rutland Railroad who, on a lovely autumn day in 1848, ignited a small explosion in the vicinity of his feet, launching a three-and-a-half-foot-long iron rod into the air, which Phineas cleverly caught with his face. The rod entered just beneath his left cheek and exited through the top of his skull, boring a tunnel through his cranium and taking a good chunk of frontal lobe with it (see figure 3). Phineas was knocked to the ground, where he lay for a few minutes. Then, to everyone’s astonishment, he stood up and asked if a coworker might escort him to the doctor, insisting all the while that he didn’t need a ride and could walk by himself, thank you. The doctor cleaned some dirt from his wound, a coworker cleaned some brain from the rod, and in a relatively short while, Phineas and his rod were back about their business.[11] His personality took a decided turn for the worse–and that fact is the source of his fame to this day–but the more striking thing about Phineas was just how normal he otherwise was. Had the rod made hamburger of another brain part–the visual cortex, Brace’s area, the brain stem–then Phineas might have died, gone blind, lost the ability to speak or spent the rest of his life doing a convincing impression of a cabbage. Instead, for the next twelve years, he lived, saw, spoke, worked and travelled so uncabbagely that neurologists could only conclude that the frontal lobe did little for a fellow that he couldn’t get along nicely without.[12] As one neurologist wrote in 1884, ‘Ever since the occurrence of the famous American crowbar case it has been known that destruction of these lobes does not necessarily give rise to any symptoms.’[13]

Fig. 3. An early medical sketch showing where the tamping iron entered and exited Phineas Gage’s skull.

But the neurologist was wrong. In the nineteenth century, knowledge of brain function was based largely on the observation of people who, like Phineas Gage, were the unfortunate subjects of one of nature’s occasional and inexact neurological experiments. In the twentieth century, surgeons picked up where nature left off and began to do more precise experiments whose results painted a very different picture of frontal lobe function. In the 1930s, a Portuguese physician named Antonio Egas Moniz was looking for a way to quiet his highly agitated psychotic patients when he heard about a new surgical procedure called frontal lobotomy, which involved the chemical or mechanical destruction of parts of the frontal lobe. This procedure had been performed on monkeys, who were normally quite angry when their food was withheld, but who reacted to such indignities with unruffled patience after experiencing the operation. Egas Moniz tried the procedure on his human patients and found that it had a similar calming effect. (It also had the calming effect of winning Egas Moniz the Nobel Prize for Medicine in 1949.) Over the next few decades, surgical techniques were improved (the procedure could be performed under local anesthesia with an ice pick) and unwanted side effects (such as lowered intelligence and bed-wetting) were diminished. The destruction of some part of the frontal lobe became a standard treatment for cases of anxiety and depression that resisted other forms of therapy.[14] Contrary to the conventional medical wisdom of the previous century, the frontal lobe did make a difference. The difference was that some people seemed better off without it.

But while some surgeons were touting the benefits of frontal lobe damage, others were noticing the costs. Although patients with frontal lobe damage often performed well on standard intelligence tests, memory tests and the like, they showed severe impairments on any test–even the very simplest test–that involved planning. For instance, when given a maze or a puzzle whose solution required that they consider an entire series of moves before making their first move, these otherwise intelligent people were stumped.[15] Their planning deficits were not limited to the laboratory. These patients might function reasonably well in ordinary situations, drinking tea without spilling and making small talk about the curtains, but they found it practically impossible to say what they would do later that afternoon. In summarizing scientific knowledge on this topic, a prominent scientist concluded: ‘No prefrontal symptom has been reported more consistently than the inability to plan…. The symptom appears unique to dysfunction of the prefrontal cortex…[and] is not associated with clinical damage to any other neural structure.’[16]

Now, this pair of observations–that damage to certain parts of the frontal lobe can make people feel calm but that it can also leave them unable to plan–seem to converge on a single conclusion. What is the conceptual tie that binds anxiety and planning? Both, of course, are intimately connected to thinking about the future. We feel anxiety when we anticipate that something bad will happen, and we plan by imagining how our actions will unfold over time. Planning requires that we peer into our futures, and anxiety is one of the reactions we may have when we do.[17] The fact that damage to the frontal lobe impairs planning and anxiety so uniquely and precisely suggests that the frontal lobe is the critical piece of cerebral machinery that allows normal, modern human adults to project themselves into the future. Without it we are trapped in the moment, unable to imagine tomorrow and hence unworried about what it may bring. As scientists now recognize, the frontal lobe ‘empowers healthy human adults with the capacity to consider the self’s extended existence throughout time’.[18]? As such, people whose frontal lobe is damaged are described by those who study them as being ‘bound to present stimuli’,[19] or ‘locked into immediate space and time’,[20] or as displaying a ‘tendency toward temporal concreteness’.[21] In other words, like candy guys and tree climbers, they live in a world without later.

The sad case of the patient known as N.N. provides a window into this world. N.N. suffered a closed head injury in an automobile accident in 1981, when he was thirty years old. Tests revealed that he had sustained extensive damage to his frontal lobe. A psychologist interviewed N.N. a few years after the accident and recorded this conversation:

PSYCHOLOGIST: What will you be doing tomorrow?

N.N.: I don’t know.

PSYCHOLOGIST: DO you remember the question?

N.N.: About what I’ll be doing tomorrow?

PSYCHOLOGIST: Yes, would you describe your state of mind when you try to think about it?

N.N.: Blank, I guess…It’s like being asleep…like being in a room with nothing there and having a guy tell you to go find a chair, and there’s nothing there…like swimming in the middle of a lake. There’s nothing to hold you up or do anything with.[22]

N.N.’s inability to think about his own future is characteristic of patients with frontal lobe damage. For N.N., tomorrow will always be an empty room, and when he attempts to envision later, he will always feel as the rest of us do when we try to imagine nonexistence or infinity. Yet, if you struck up a conversation with N.N. on the subway, or chatted with him while standing in a queue at the post office, you might not know that he was missing something so fundamentally human. After all, he understands time and the future as abstractions. He knows what hours and minutes are, how many of the latter there are in the former, and what before and after mean. As the psychologist who interviewed N.N. reported: “He knows many things about the world, he is aware of this knowledge, and he can express it flexibly. In this sense he is not greatly different from a normal adult. But he seems to have no capacity of experiencing extended subjective time…. He seems to be living in a ‘permanent present…’”[23]

A permanent present–what a haunting phrase. How bizarre and surreal it must be to serve a life sentence in the prison of the moment, trapped forever in the perpetual now, a world without end, a time without later. Such an existence is so difficult for most of us to imagine, so alien to our normal experience, that we are tempted to dismiss it as a fluke–an unfortunate, rare and freakish aberration brought on by traumatic head injury. But in fact, this strange existence is the rule and we are the exception. For the first few hundred million years after their initial appearance on our planet, all brains were stuck in the permanent present, and most brains still are today. But not yours and not mine, because two or three million years ago our ancestors began a great escape from the here and now, and their getaway vehicle was a highly specialized mass of grey tissue, fragile, wrinkled and appended. This frontal lobe–the last part of the human brain to evolve, the slowest to mature and the first to deteriorate in old age–is a time machine that allows each of us to vacate the present and experience the future before it happens. No other animal has a frontal lobe quite like ours, which is why we are the only animal that thinks about the future as we do. But if the story of the frontal lobe tells us bow people conjure their imaginary tomorrows, it doesn’t tell us why.

Twisting Fate

In the late 1960s, a Harvard psychology professor took LSD, resigned his appointment (with some encouragement from the administration), went to India, met a guru and returned to write a popular book called Be Here Now, whose central message was succinctly captured by the injunction of its title.[24] The key to happiness, fulfilment and enlightenment, the ex-professor argued, was to stop thinking so much about the future.

Now, why would anyone go all the way to India and spend his time, money and brain cells just to learn how not to think about the future? Because, as anyone who has ever tried to learn meditation knows, not thinking about the future is much more challenging than being a psychology professor. Not to think about the future requires that we convince our frontal lobe not to do what it was designed to do, and like a heart that is told not to beat, it naturally resists this suggestion. Unlike N.N., most of us do not struggle to think about the future because mental simulations of the future arrive in our consciousness regularly and unbidden, occupying every corner of our mental lives. When people are asked to report how much they think about the past, present and future, they claim to think about the future the most.[25] When researchers actually count the items that float along in the average person’s stream of consciousness, they find that about 12 per cent of our daily thoughts are about the future.[26]? In other words, every eight hours of thinking includes an hour of thinking about things that have yet to happen. If you spent one out of every eight hours living in my state you would be required to pay taxes, which is to say that in some very real sense, each of us is a part-time resident of tomorrow.

Why can’t we just be here now? How come we can’t do something our goldfish find so simple? Why do our brains stubbornly insist on projecting us into the future when there is so much to think about right here today?

Prospection and Emotion

The most obvious answer to that question is that thinking about the future can be pleasurable. We daydream about hitting a home-run at the company picnic, posing with the lottery commissioner and the door-sized cheque, or making snappy patter with the attractive teller at the bank–not because we expect or even want these things to happen, but because merely imagining these possibilities is itself a source of joy. Studies confirm what you probably suspect: when people daydream about the future, they tend to imagine themselves achieving and succeeding rather than fumbling or failing.[27]

Indeed, thinking about the future can be so pleasurable that sometimes we’d rather think about it than get there. In one study, volunteers were told that they had won a free dinner at a fabulous French restaurant and were then asked when they would like to eat it. Now? Tonight? Tomorrow? Although the delights of the meal were obvious and tempting, most of the volunteers chose to put their restaurant visit off a bit, generally until the following week.[28]? Why the self-imposed delay? Because by waiting a week, these people not only got to spend several hours slurping oysters and sipping Chateau Cheval Blanc ’47, but they also got to look forward to all that slurping and sipping for a full seven days beforehand. Forestalling pleasure is an inventive technique for getting double the juice from half the fruit. Indeed, some events are more pleasurable to imagine than to experience (most of us can recall an instance in which we made love with a desirable partner or ate a wickedly rich dessert, only to find that the act was better contemplated than consummated), and in these cases people may decide to delay the event forever. For instance, volunteers in one study were asked to imagine themselves requesting a date with a person on whom they had a major crush, and those who had had the most elaborate and delicious fantasies about approaching their heartthrob were least likely to do so over the next few months.[29]

We like to frolic in the best of all imaginary tomorrows–and why shouldn’t we? After all, we fill our photo albums with pictures of birthday parties and tropical holidays rather than car wrecks and emergency-room visits because we want to be happy when we stroll down Memory Lane, so why shouldn’t we take the same attitude toward our strolls up Imagination Avenue? Although imagining happy futures may make us feel happy, it can also have some troubling consequences. Researchers have discovered that when people find it easy to imagine an event, they overestimate the likelihood that it will actually occur.[30] Because most of us get so much more practice imagining good than bad events, we tend to overestimate the likelihood that good events will actually happen to us, which leads us to be unrealistically optimistic about our futures.

For instance, American college students expect to live longer, stay married longer and travel to Europe more often than averages[31] They believe they are more likely to have a gifted child, to own their own home and to appear in the newspaper, and less likely to have a heart attack, venereal disease, a drinking problem, an auto accident, a broken bone or gum disease. Americans of all ages expect their futures to be an improvement on their presents[32] and although citizens of other nations are not quite as optimistic as Americans, they also tend to imagine that their futures will be brighter than those of their peers.[33] These overly optimistic expectations about our personal futures are not easily undone: experiencing an earthquake causes people to become temporarily realistic about their risk of dying in a future disaster, but within a couple of weeks even earthquake survivors return to their normal level of unfounded optimisms.[34] Indeed, events that challenge our optimistic beliefs can sometimes make us more rather than less optimistic. One study found that cancer patients were more optimistic about their futures than were their healthy counterparts.[35]

Of course, the futures that our brains insist on simulating are not all wine, kisses and tasty bivalves. They are often mundane, irksome, stupid, unpleasant or downright frightening, and people who seek treatment for their inability to stop thinking about the future are usually worrying about it rather than revelling in it. Just as a loose tooth seems to beg for wiggling, we all seem perversely compelled to imagine disasters and tragedies from time to time. On the way to the airport we imagine a future scenario in which the plane takes off without us and we miss the important meeting with the client. On the way to the dinner party we imagine a future scenario in which everyone hands the hostess a bottle of wine while we greet her empty-handed and embarrassed. On the way to the medical centre we imagine a future scenario in which our doctor inspects our chest X-ray, frowns and says something ominous such as ‘Let’s talk about your options.’ These dire images make us feel dreadful–quite literally–so why do we go to such great lengths to construct them?

Two reasons. First, anticipating unpleasant events can minimize their impact. For instance, volunteers in one study received a series of twenty electric shocks and were warned three seconds before the onset of each one.[36] Some volunteers (the high-shock group) received twenty high-intensity shocks to their right ankles. Other volunteers (the low-shock group) received three high-intensity shocks and seventeen low-intensity shocks. Although the low-shock group received fewer volts than the high-shock group did, their hearts beat faster, they sweated more profusely and they rated themselves as more afraid. Why? Because volunteers in the low-shock group received shocks of different intensities at different times, which made it impossible for them to anticipate their futures. Apparently, three big jolts that one cannot foresee are more painful than twenty big jolts that one can.[37]

The second reason why we take such pains to imagine unpleasant events is that fear, worry and anxiety have useful roles to play in our lives. We motivate employees, children, spouses and pets to do the right thing by dramatizing the unpleasant consequences of their misbehaviours, and so too do we motivate ourselves by imagining the unpleasant tomorrows that await us should we decide to go light on the sunscreen and heavy on the éclairs. Forecasts can be ‘fearcasts.’[38] whose purpose is not to predict the future so much as to preclude it, and studies have shown that this strategy is often an effective way to motivate people to engage in prudent, prophylactic behavior.[39] In short, we sometimes imagine dark futures just to scare our own pants off.

Prospection and Control

Prospection can provide pleasure and prevent pain, and this is one of the reasons why our brains stubbornly insist on churning out thoughts of the future. But it is not the most important reason. Americans gladly pay millions–perhaps even billions–of dollars every year to psychics, investment advisors, spiritual leaders, weather forecasters and other assorted hucksters who claim they can predict the future. Those of us who subsidize these fortune-telling industries do not want to know what is likely to happen just for the joy of anticipating it. We want to know what is likely to happen so that we can do something about it. If interest rates are going to skyrocket next month, then we want to shift our money out of bonds right now. If it is going to rain this afternoon, then we want to grab an umbrella this morning. Knowledge is power, and the most important reason why our brains insist on simulating the future even when we’d rather be here now, enjoying a goldfish moment, is that our brains want to control the experiences we are about to have.

But why should we want to have control over our future experiences? On the face of it, this seems about as nonsensical as asking why we should want to have control over our television sets and our automobiles. But indulge me. We have a large frontal lobe so that we can look into the future, we look into the future so that we can make predictions about it, we make predictions about it so that we can control it–but why do we want to control it at all? Why not just let the future unfold as it will and experience it as it does? Why not be here now and there then? There are two answers to this question, one of which is surprisingly right and the other of which is surprisingly wrong.

The surprisingly right answer is that people find it gratifying to exercise control–not just for the futures it buys them, but for the exercise itself. Being effective–changing things, influencing things, making things happen–is one of the fundamental needs with which human brains seem to be naturally endowed, and much of our behavior from infancy onward is simply an expression of this penchant for control.[40] Before our butts hit the very first nappy, we already have a throbbing desire to suck, sleep, poo and make things happen. It takes us a while to get around to fulfilling the last of these desires only because it takes us a while to figure out that we have fingers, but when we do, look out world. Toddlers squeal with delight when they knock over a stack of blocks, push a ball or squash a cupcake on their foreheads. Why? Because they did it, that’s why. Look, Mum, my hand made that happen. The room is different because I was in it. I thought about falling blocks, and poof, they fell.

The fact is that human beings come into the world with a passion for control, they go out of the world the same way, and research suggests that if they lose their ability to control things at any point between their entrance and their exit, they become unhappy, helpless, hopeless and depressed.[41] And occasionally dead. In one study, researchers gave elderly residents of a local nursing home a house-plant. They told half the residents that they were in control of the plant’s care and feeding (high-control group), and they told the remaining residents that a staff person would take responsibility for the plant’s well-being (low-control group).4[42] Six months later, 30 per cent of the residents in the low-control group had died, compared with only 15 per cent of the residents in the high-control group. A follow-up study confirmed the importance of perceived control for the welfare of nursing-home residents but had an unexpected and unfortunate end.[43] Researchers arranged for student volunteers to pay regular visits to nursing-home residents. Residents in the high-control group were allowed to control the timing and duration of the student’s visit (‘Please come visit me next Thursday for an hour’), and residents in low-control group were not (‘I’ll come visit you next Thursday for an hour’). After two months, residents in the high-control group were happier, healthier, more active and taking fewer medications than those in the low-control group. At this point the researchers concluded their study and discontinued the student visits. Several months later they were chagrined to learn that a disproportionate number of residents who had been in the high-control group had died. Only in retrospect did the cause of this tragedy seem clear. The residents who had been given control, and who had benefited measurably from that control while they had it, were inadvertently robbed of control when the study ended.

Apparently, gaining control can have a positive impact on one’s health and well-being, but losing control can be worse than never having had any at all.

Our desire to control is so powerful, and the feeling of being in control so rewarding, that people often act as though they can control the uncontrollable. For instance, people bet more money on games of chance when their opponents seem incompetent than competent–as though they believed they could control the random drawing of cards from a deck and thus take advantage of a weak opponent.[44] People feel more certain that they will win a lottery if they can control the number on their tickets,[45] and they feel more confident that they will win a dice toss if they can throw the dice themselves.[46] People will wager more money on dice that have not yet been tossed than on dice that have already been tossed but whose outcome is not yet known,[47] and they will bet more if they, rather than someone else, are allowed to decide which number will count as a win.[48] In each of these instances, people behave in a way that would be utterly absurd if they believed that they had no control over an uncontrollable event. But if somewhere deep down inside they believed that they could exert control–even one smidgen of an iota of control–then their behavior would be perfectly reasonable. And deep down inside, that’s precisely what most of us seem to believe. Why isn’t it fun to watch a videotape of last night’s football game even when we don’t know who won? Because the fact that the game has already been played precludes the possibility that our cheering will somehow penetrate the television, travel through the cable system, find its way to the stadium, and influence the trajectory of the ball as it hurtles toward the goalposts! Perhaps the strangest thing about this illusion of control is not that it happens but that it seems to confer many of the psychological benefits of genuine control. In fact, the one group of people who seem generally immune to this illusion are the clinically depressed,[49] who tend to estimate accurately the degree to which they can control events in most situations.[50] These and other findings have led some researchers to conclude that the feeling of control–whether real or illusory–is one of the wellsprings of mental health.[51] So if the question is ‘Why should we want to control our futures?’ then the surprisingly right answer is that it feels good to do so–period. Impact is rewarding. Mattering makes us happy. The act of steering one’s boat down the river of time is a source of pleasure, regardless of one’s port of call.

Now, at this point you probably believe two things. First, you probably believe that if you never heard the phrase “the river of time” again, it would be too soon. Amen. Second, you probably believe that even if the act of steering a metaphorical boat down a clichéd river is a source of pleasure and well-being, where the boat goes matters much, much more. Playing captain is a joy all its own, but the real reason why we want to steer our ships is so that we can get them to Hanalei instead of Jersey City. The nature of a place determines how we feel upon arrival, and our uniquely human ability to think about the extended future allows us to choose the best destinations and avoid the worst. We are the apes that learned to look forward because doing so enables us to shop among the many fates that might befall us and select the best one. Other animals must experience an event in order to learn about its pleasures and pains, but our powers of foresight allow us to imagine that which has not yet happened and hence spare ourselves the hard lessons of experience. We needn’t reach out and touch an ember to know that it will hurt to do so, and we needn’t experience abandonment, scorn, eviction, demotion, disease or divorce to know that all of these are undesirable ends that we should do our best to avoid. We want–and we should want–to control the direction of our boat because some futures are better than others, and even from this distance we should be able to tell which are which.

This idea is so obvious that it barely seems worth mentioning, but I’m going to mention it anyway. Indeed, I am going to spend the rest of this book mentioning it because it will probably take more than a few mentions to convince you that what looks like an obvious idea is, in fact, the surprisingly wrong answer to our question. We insist on steering our boats because we think we have a pretty good idea of where we should go, but the truth is that much of our steering is in vain–not because the boat won’t respond, and not because we can’t find our destination, but because the future is fundamentally different than it appears through the prospectiscope. Just as we experience illusions of eyesight (‘Isn’t it strange how one queue looks longer than the other even though it isn’t?’) and illusions of hindsight (‘Isn’t it strange how I can’t remember taking out the garbage even though I did?’), so too do we experience illusions of foresight–and all three types of illusion are explained by the same basic principles of human psychology.

Onward

To be perfectly honest, I won’t just be mentioning the surprisingly wrong answer; I’ll be pounding and pummelling it until it gives up and goes home. The surprisingly wrong answer is apparently so sensible and so widely believed that only a protracted thrashing has any hope of expunging it from our conventional wisdom. So before the grudge match begins, let me share with you my plan of attack.

• In Part II, ‘Subjectivity’, I will tell you about the science of happiness. We all steer ourselves toward the futures that we think will make us happy, but what does that word really mean? And how can we ever hope to achieve solid, scientific answers to questions about something as gossamer as a feeling?

• We use our eyes to look into space and our imaginations to look into time. Just as our eyes sometimes lead us to see things as they are not, our imaginations sometimes lead us to foresee things as they will not be. Imagination suffers from three shortcomings that give rise to the illusions of foresight with which this book is chiefly concerned. In Part III, ‘Realism’, I will tell you about the first shortcoming: imagination works so quickly, quietly, and effectively that we are insufficiently sceptical of its products.

• In Part IV, ‘Presentism’, I will tell you about the second shortcoming: Imagination’s products are…well, not particularly imaginative, which is why the imagined future often looks so much like the actual present.

• In Part V, ‘Rationalization’, I will tell you about the third shortcoming: imagination has a hard time telling us how we will think about the future when we get there. If we have trouble foreseeing future events, then we have even more trouble foreseeing how we will see them when they happen.

• Finally, in Part VI, ‘Corrigibility’, I will tell you why illusions of foresight are not easily remedied by personal experience or by the wisdom we inherit from our grandmothers. I will conclude by telling you about a simple remedy for these illusions that you will almost certainly not accept.

By the time you finish these chapters, I hope you will understand why most of us spend so much of our lives turning rudders and hoisting sails, only to find that Shangri-la isn’t what and where we thought it would be.