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.
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
prospection(pro•spe•kshen) The act of looking forward in time or considering the future.
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.1
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