As I started to question my assumptions, I began to see cracks in the façade of the Temple of Rationality. I saw that pacts of complicity between deceivers and self-deceivers are not only ubiquitous, but often useful, regularly functional and sometimes essential. They can shape the quality of our relationships. They can underpin the success of our groups. They can even predict how long we’ll live.
Believing what we want to believe, and seeing what we want to see, I slowly came to understand, is less a state of mind, or a reflection of one’s intelligence, and more a response to one’s circumstances. Foregoing self-deception isn’t merely a mark of education or enlightenment — it is a sign of privilege. If you don’t believe in Santa Claus or the Virgin Birth, it’s because your life does not depend on your believing such things. Your material, cultural and social worlds are providing you with other safety nets for your psychological and physical needs. But should your circumstances change for the worse, were the pillars of your life to buckle and sway, your mind, too, would prove fertile ground for the wildest self-deceptions. There are, as we say, no atheists in foxholes.
At the core of our troubled relationship with the truth lies a dilemma: We need hope in order to function, but the world gives us endless reasons not to be hopeful. For most people on the planet, to forswear self- deception is to invite despair and dysfunction. This is especially clear when you step back and look at the big picture: If all life on earth was mapped on a timeline that stretched one hundred yards in length, humans arrived on the scene an eighth of an inch from the very end. All of human history— the rise and fall of every empire, every score of music and every book ever written, all the vast encyclopedias of human knowledge— everything falls into that last tiny sliver. If you step back even further, and look not just at life on earth but at our planet itself, human beings vanish into total insignificance: Earth is one of a hundred billion planets, and that’s just in our galaxy. That galaxy is one of two trillion galaxies. Humans are a tiny and fragile part of a very big universe. Our own existence as individuals? That’s even more fragile, by many orders of magnitude.
How does this make you feel? Understanding something about the scale of time and space can produce wonder. But awareness of our own insignificance can also be a source of deep terror and dejection. In the very near future lie irrelevance, oblivion and erasure. If we were to speak truthfully, each of our lives is trivial, unimportant and utterly forgettable. This is not a useful attitude when it comes to ensuring our survival and the survival of our genes. If we are to roll the Sisyphean boulder up and down the hill, as required for our survival and the well-being of our progeny, it isn’t helpful to feel our lives are useless or unimportant. This is why, in every culture around the world, people reach for beliefs that tell them that their lives have purpose and meaning. Nations and tribes convince us that, by becoming part of large groups, we can transcend our own brief existence as individuals. Nearly every religion in the world offers reassurances about what happens to you after you die. Poking holes in these claims is easy, because they are often illogical and far-fetched. Books such as The God Delusion by Richard Dawkins advise us to peer fearlessly into the void, to accept our irrelevance with good cheer. But this belies the real challenge: Most people without endowed professorships at Oxford University find it difficult to think of their own unimportance with equanimity. In fact, in a meeting at his beautiful home at Oxford some years ago, I asked Dawkins this question: Separate from whether the claims made by religions are true, should a person experiencing great suffering, but who feels their life is made bearable by a religious belief in the afterlife, be stripped of the comfort of their convictions? Dawkins was silent. If you’re the kind of person who believes people with terminal illnesses should be stripped of their illusions about a heavenly afterlife, you sound the way I sounded in my twenties. Fine. But remember this: If self-deception is functional, then it will endure, regardless of all the best sellers that criticize it. Life, like evolution and natural selection, ultimately doesn’t care about what’s true. It cares about what works.
Consider this simplest of examples — the organ you are using to read this book: In any given second, the human eye collects about a billion bits of information. This flood of data is compressed a thousand times, and only one million bits of information are sent to the brain via the optic nerve. The brain keeps just forty bits of this data, and discards the rest. As the cognitive psychologist and author Donald Hoffman explains, this is like taking an actual book, compressing the chapters into Cliffs Notes, then taking those notes and throwing away nearly everything until you are left with a blurb.
The amazing thing is not that your brain reduces books to blurbs on a moment-to-moment basis: It is that your brain gives you the illusion that you are seeing everything, that you are taking in the whole book. An engineer might say that what has unfolded is a profound delusion— what we think we see bears almost no resemblance to reality. But most of us would say that, subjectively, it feels, well, normal. It turns out there are excellent reasons for your eyes and brain to do all this filtering. Indeed, to see reality clearly would leave us worse off, not better. Our eyes and brain are not in the truth business; they are in the functionality business, and it turns out that discarding nine hundred and ninety- nine million, nine hundred and ninety- nine thousand, nine hundred and sixty bits of data out of every billion is extremely functional.
What happens with visual information also happens in nearly every part of our mental lives. We think we are seeing, hearing and processing the truth, but we often are not. As with our eyes, it turns out there are excellent reasons to prioritize functionality over reality in every domain. Yes, this means you miss the truth, but it gets you to the real goal: Your brain has been designed to help you survive, to forage for opportunities, to get along with mates and friends, to raise offspring to adulthood, and to avoid feelings of existential despair. From the perspective of evolution, objective truth is not only not the goal, it is not even the only path to the goal.
Read more about Useful Delusions on our books page.