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Stumbling on Happiness
Daniel Gilbert
In this fascinating and often hilarious work – winner of the Royal Society of Science Prize 2007 – pre-eminent psychologist Daniel Gilbert shows how – and why – the majority of us have no idea how to make ourselves happy.
We all want to be happy, but do we know how? When it comes to improving tomorrow at the expense of today, we're terrible at predicting how to please our future selves.
In ‘Stumbling on Happiness’ Professor Daniel Gilbert combines psychology, neuroscience, economics and philosophy with irrepressible wit to describe how the human brain imagines its future – and how well (or badly) it predicts what it will enjoy. Revealing some of the amazing secrets of human motivation, he also answers thought-provoking questions – why do dining companions order different meals instead of getting what they want? Why are shoppers happier when they can't get refunds? And why are couples less satisfied after having children while insisting that their kids are a source of joy?
Daniel Gilbert
Stumbling on Happiness
Copyright
William Collins
An imprint of HarperCollinsPublishers Ltd.
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This edition published by Harper Perennial 2007
First published in Great Britain by Harper Press in 2006
Copyright © Daniel Gilbert 2006
PS Section copyright © Clare Garner 2007, except ‘Confessions of a Spoondigger’ by Daniel Gilbert © Daniel Gilbert 2007
PS
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Daniel Gilbert asserts the moral right to be identified as the author of this work
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Praise
From the reviews of Stumbling on Happiness:
‘The joy of this book lies in the reading … there are dozens of books that contain the science, but this one pulls it all together in the neatest, wittiest way possible. If you didn’t laugh at the parade of human folly laid out in this book, you’d have to cry. In fact, if you are like this reviewer you will giggle, splutter, guffaw and then possibly fall off your chair making weird wheezing noises’
Daily Mail
‘A witty, insightful and superbly entertaining trek through the foibles of human imagination’
New Scientist
‘A delight to read. Gilbert is charming and funny and has a rare gift for making very complicated ideas come alive. He walks us through a series of fascinating – and in some ways troubling – facts about the way our minds work. This is a psychological detective story about one of the great mysteries of our lives. If you have even the slightest curiosity about the human condition, you ought to read it. Trust me’
MALCOLM GLADWELL, author of The Tipping Point
‘A cerebral, intelligent and extremely entertaining account of our lifetime quest for deep satisfaction. He eloquently combines philosophy and science to unravel the deep mystery of our baseline emotional state … he does for psychology what Bill Bryson did for evolution’
Scotsman
‘Stumbling on Happiness is an absolutely fantastic book that will shatter your most deeply held convictions about how your own mind works. Ceaselessly entertaining, Gilbert is the perfect guide to some of the most interesting psychological research ever performed. Think you know what makes you happy? You won’t know for sure until you have read this book’
STEVE LEVITT, author of Freakonomics
‘In Stumbling on Happiness, Daniel Gilbert shares his brilliant insights into our quirks of mind, and steers us toward happiness in the most delightful, engaging ways. If you stumble on this book, you’re guaranteed many doses of joy’
DANIEL GOLEMAN, author of Emotional Intelligence
‘This is a brilliant book, a useful book, and a book that could quite possibly change the way you look at just about everything. And as a bonus, Gilbert writes like a cross between Malcolm Gladwell and David Sedaris’
SETH GODIN, author of All Marketers Are Liars
‘Everyone will enjoy reading this book, and some of us will wish we could have written it. You will rarely have a chance to learn so much about so important a topic while having so much fun’
PROFESSOR DANIEL KAHNEMAN, Princeton University, Winner of the 2002 Nobel Prize in Economics
‘Gilbert is a lively and amusing stylist… beautifully written and thoroughly researched’
Sunday Telegraph
‘Gilbert is the most entertaining happiness thinker. In Stumbling on Happiness, there is much to admire’
Financial Times
‘Scientific erudition enlivened by acerbic wit’
The Times
‘Gilbert is every bit as funny as Larry David… [He] translates and makes sense of a vast array of scientific literature on perception, memory and imagination. Among other things, Gilbert explains why we learn so little from our mistakes. Almost every page delivers enjoyable riffs’
Washington Post
‘A fascinating new book that explores our sometimes misguided attempts to find happiness’
Time
‘Gilbert’s elbow-in-the-ribs social-science humor is actually funny… But underneath the goofball brilliance, [he] has a serious argument to make about why human beings are forever wrongly predicting what will make them happy’
New York Times
‘[Gilbert is] an engaging and amiable writer, with a penchant for comedy and cracking wise … but though the delivery may often be antic, the matter is serious…. Reading his engaging, accessible book made me happy. Even if it won’t last’
The Globe and Mail
Dedication
For Oli, under the apple tree
One cannot divine nor forecast the conditions that will make happiness; one only stumbles upon them by chance, in a lucky hour, at the world’s end somewhere, and holds fast to the days, as to fortune or fame.
Willa Cather, ‘Le Lavandou’, 1902
FOREWORD
How sharper than a serpent’s tooth it is To have a thankless child.
Shakespeare, King Lear
WHAT WOULD YOU DO right now if you learned that you were going to die in ten minutes? Would you race upstairs and light that Marlboro you’ve been hiding in your sock drawer since the Ford administration? Would you waltz into your boss’s office and present him with a detailed description of his personal defects? Would you drive out to that steakhouse near the new mall and order a T-bone, medium rare, with an extra side of the really bad cholesterol? Hard to say, of course, but of all the things you might do in your final ten minutes, it’s a pretty safe bet that few of them are things you actually did today.
Now, some people will bemoan this fact, wag their fingers in your direction, and tell you sternly that you should live every minute of your life as though it were your last, which only goes to show that some people would spend their final ten minutes giving other people dumb advice. The things we do when we expect our lives to continue are naturally and properly different than the things we might do if we expected them to end abruptly. We go easy on the lard and tobacco, smile dutifully at yet another of our boss’s witless jokes, read books like this one when we could be wearing paper hats and eating pistachio macaroons in the bathtub, and we do each of these things in the charitable service of the people we will soon become. We treat our future selves as though they were our children, spending most of the hours of most of our days constructing tomorrows that we hope will make them happy. Rather than indulging in whatever strikes our momentary fancy, we take responsibility for the welfare of our future selves, squirrelling away portions of our paycheques each month so they can enjoy their retirements on a putting green, jogging and flossing with some regularity so they can avoid coronaries and gum grafts, enduring dirty nappies and mind-numbing repetitions of The Cat in the Hat so that someday they will have fat-cheeked grandchildren to bounce on their laps. Even plunking down a dollar at the convenience store is an act of charity intended to ensure that the person we are about to become will enjoy the cupcake we are paying for now. In fact, just about any time we want something–a promotion, a marriage, an automobile, a cheeseburger–we are expecting that if we get it, then the person who has our fingerprints a second, minute, day or decade from now will enjoy the world they inherit from us, honoring our sacrifices as they reap the harvest of our shrewd investment decisions and dietary forbearance.
Yeah, yeah. Don’t hold your breath. Like the fruits of our loins, our temporal progeny are often thankless. We toil and sweat to give them just what we think they will like, and they quit their jobs, grow their hair, move to or from San Francisco and wonder how we could ever have been stupid enough to think they’d like that. We fail to achieve the accolades and rewards that we consider crucial to their well-being, and they end up thanking God that things didn’t work out according to our shortsighted, misguided plan. Even that person who takes a bite of the cupcake we purchased a few minutes earlier may make a sour face and accuse us of having bought the wrong snack. No one likes to be criticized, of course, but if the things we successfully strive for do not make our future selves happy, or if the things we unsuccessfully avoid do, then it seems reasonable (if somewhat ungracious) for them to cast a disparaging glance backward and wonder what the hell we were thinking. They may recognize our good intentions and begrudgingly acknowledge that we did the best we could, but they will inevitably whine to their therapists about how our best just wasn’t good enough for them.
How can this happen? Shouldn’t we know the tastes, preferences, needs and desires of the people we will be next year–or at least later this afternoon? Shouldn’t we understand our future selves well enough to shape their lives–to find careers and lovers whom they will cherish, to buy slipcovers for the sofa that they will treasure for years to come? So why do they end up with attics and lives that are full of stuff that we considered indispensable and that they consider painful, embarrassing or useless? Why do they criticize our choice of romantic partners, second-guess our strategies for professional advancement and pay good money to remove the tattoos that we paid good money to get? Why do they experience regret and relief when they think about us, rather than pride and appreciation? We might understand all this if we had neglected them, ignored them, mistreated them in some fundamental way–but damn it, we gave them the best years of our lives! How can they be disappointed when we accomplish our coveted goals, and why are they so damned giddy when they end up in precisely the spot that we worked so hard to steer them clear of? Is there something wrong with them?
Or is there something wrong with us?
WHEN I WAS TEN YEARS OLD, the most magical object in my house was a book on optical illusions. Its pages introduced me to the Müller-Lyer lines whose arrow-tipped ends made them appear as though they were different lengths even though a ruler showed them to be identical, the Necker cube that appeared to have an open side one moment and then an open top the next, the drawing of a chalice that suddenly became a pair of silhouetted faces before flickering back into a chalice again (see figure 1). I would sit on the floor in my father’s study and stare at that book for hours, mesmerized by the fact that these simple drawings could force my brain to believe things that it knew with utter certainty to be wrong. This is when I learned that mistakes are interesting and began planning a life that contained several of them. But an optical illusion is not interesting simply because it causes everyone to make a mistake; rather, it is interesting because it causes everyone to make the same mistake. If I saw a chalice, you saw Elvis and a friend of ours saw a paper carton of moo goo gai pan, then the object we were looking at would be a very fine inkblot but a lousy optical illusion. What is so compelling about optical illusions is that everyone sees the chalice first, the faces next, and then–flicker flicker–there’s that chalice again. The errors that optical illusions induce in our perceptions are lawful, regular and systematic. They are not dumb mistakes but smart mistakes–mistakes that allow those who understand them to glimpse the elegant design and inner workings of the visual system.
Fig. 1.
The mistakes we make when we try to imagine our personal futures are also lawful, regular and systematic. They too have a pattern that tells us about the powers and limits of foresight in much the same way that optical illusions tell us about the powers and limits of eyesight. That’s what this book is all about. Despite the third word of the title, this is not an instruction manual that will tell you anything useful about how to be happy. Those books are located in the self-help section two aisles over, and once you’ve bought one, done everything it says to do and found yourself miserable anyway, you can always come back here to understand why. Instead, this is a book that describes what science has to tell us about how and how well the human brain can imagine its own future, and about how and how well it can predict which of those futures it will most enjoy. This book is about a puzzle that many thinkers have pondered over the last two millennia, and it uses their ideas (and a few of my own) to explain why we seem to know so little about the hearts and minds of the people we are about to become. The story is a bit like a river that crosses borders without benefit of passport because no single science has ever produced a compelling solution to the puzzle. Weaving together facts and theories from psychology, cognitive neuroscience, philosophy and behavioural economics, this book allows an account to emerge that I personally find convincing but whose merits you will have to judge for yourself.
Writing a book is its own reward, but reading a book is a commitment of time and money that ought to pay clear dividends. If you are not educated and entertained, you deserve to be returned to your original age and net worth. That won’t happen, of course, so I’ve written a book that I hope will interest and amuse you, provided you don’t take yourself too seriously and have at least ten minutes to live. No one can say how you will feel when you get to the end of this book, and that includes the you who is about to start it. But if your future self is not satisfied when it arrives at the last page, it will at least understand why you mistakenly thought it would be.[1 - The notes in this book contain references to the scientific research that supports the claims I make in the text. Occasionally they contain some extra information that may be of interest but that is not essential to the argument. If you don’t care about sources, aren’t interested in nonessentials and are annoyed by books that make you flip back and forth all the time, then be assured that the only important note in the book is this one.]
PART I
Prospection
prospection (pro•spe•kshen)
The act of looking forward in time or considering the future.
CHAPTER I
Journey to Elsewhen
O, that a man might know
The end of this day’s business ere it comes!
Shakespeare, Julius Caesar
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 - W. A. Roberts, ‘Are Animals Stuck in Time?’, Psychological Bulletin 128: 473-89 (2002).]
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 - D. Dennett, Kinds of Minds (New York: Basic Books, 1996).]
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 - M. M. Haith, ‘The Development of Future Thinking as Essential for the Emergence of Skill in Planning’, in The Developmental Psychology of Planning: Why, How, and When Do We Plan?, ed. S. L. Friedman and E. K. Scholnick (Mahwah, NJ: Lawrence Erlbaum, 1997), 25-42.] 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 - E. Bates, J. Elman and P. Li, ‘Language In, On, and About Time’, in The Development of Future Oriented Processes, ed. M. M. Haith et al. (Chicago: University of Chicago Press, 1994).] 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 - B. M. Hood et al., ‘Gravity Biases in a Nonhuman Primate?’, Developmental Science 2: 35-41 (1999). See also D. A. Washburn and D. M. Rumbaugh, ‘Comparative Assessment of Psychomotor Performance: Target Prediction by Humans and Macaques (Macaca mulatta)’, Journal of Experimental Psychology: General 121: 305-12 (1992).] 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 - L. M. Oakes and L. B. Cohen, ‘Infant Perception of a Causal Event’, Cognitive Development 5: 193-207 (1990). See also N. Wentworth and M. M. Haith, ‘Event-Specific Expectations of 2- and 3-Month-Old Infants’, Developmental Psychology 28: 842-50 (1992).] 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 - C. M. Atance and D. K. O’Neill, ‘Planning in 3-Year-Olds: A Reflection of the Future Self?’, in The Self in Time: Developmental Perspectives, ed. C. Moore and K. Lemmon (Mahwah, NJ: Lawrence Erlbaum, 2001); and J. B. Benson, ‘The Development of Planning: It’s About Time’, in Friedman and Scholnick, Developmental Psychology of Planning.] 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 - Although children begin to talk about the future at about two years, they don’t seem to have a full understanding of it until about age four. See D. J. Povinelli and B. B. Simon, ‘Young Children’s Understanding of Briefly Versus Extremely Delayed Images of the Self: Emergence of the Autobiographical Stance’, Developmental Psychology 34: 188-94 (1998); and K. Nelson, ‘Finding One’s Self in Time’, in The Self Across Psychology: Self-Recognition, Self-Awareness, and the Self Concept, ed. J. G. Snodgrass and R. L. Thompson (New York: New York Academy of Sciences, 1997), 103-16.]
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 - C. A. Banyas, ‘Evolution and Phylogenetic History of the Frontal Lobes’, in The Human Frontal Lobes, ed. B. L. Miller and J. L. Cummings (New York: Guilford Press, 1999), 83-106.]
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 - Phineas apparently took the rod with him wherever he went for the rest of his life and would probably be pleased that both it and his skull ended up on permanent display at Harvard’s Warren Anthropological Museum.] 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 - Modern authors cite the Gage case as evidence for the importance of the frontal lobe, but this is not the way people thought about the incident when it happened. See M. B. Macmillan, ‘A Wonderful Journey Through Skull and Brains: The Travels of Mr. Gage’s Tamping Iron’, Brain and Cognition 5: 67-107 (1986).] 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 - M. B. Macmillan, ‘Phineas Gage’s Contribution to Brain Surgery’, Journal of the History of the Neurosciences 5: 56-77 (1996).]
Fig. 3. An early medical sketch showing where the tamping iron entered and exited Phineas Gage’s skull.
