The first book of the Bible explains what happens when we disobey a great authority: We get ejected from paradise. This is also what less celestial authorities would have us believe—political pundits, scientists, doctors, CEOs, economists, government heads, sports commentators, consultants, and stock market gurus.
In the previous chapter, we met the father of all fallacies, the confirmation bias. Here are a few examples of it: We are forced to establish beliefs about the world, our lives, the economy, investments, our careers, and more. We deal mostly in assumptions, and the more nebulous these are, the stronger the confirmation bias. Whether you go through life believing that “people are inherently good” or “people are inherently bad,” you will find daily proof to support your case. Both parties, the philanthropists and the misanthropes, simply filter disconfirming evidence (evidence to the contrary) and focus on the do-gooders and dictators who support their worldviews.
Gil wants to lose weight. He selects a particular diet and checks his progress on the scale every morning. If he has lost weight, he pats himself on the back and considers the diet a success. If he has gained weight, he writes it off as a normal fluctuation and forgets about it. For months, he lives under the illusion that the diet is working, even though his weight remains constant. Gil is a victim of the confirmation bias—albeit a harmless form of it.
Not so long ago, you may have come across disciples of the Hare Krishna sect floating around in saffron-colored robes as you hurried to catch a flight or a train to your destination. A member of the sect presented you with a small flower and a smile. If you’re like most people, you took the flower simply to avoid seeming rude. If you tried to refuse, you would have heard a gentle “Take it, this is our gift to you.” If you wanted to dispose of the flower in the next trash can, you found that there were already a few there. But that was not the end. Just as your bad conscience started to tug at you, another disciple of Krishna approached you again, this time asking for a donation. In many cases, this plea was successful—so pervasive that many airports banned the sect from the premises.
The film was dire. After an hour, I (Rolf Dobelli) whispered to my wife: “Come on, let’s go home.” She replied: “No way. We’re not throwing away thirty dollars.” “That’s no reason to stay,” I protested. “The money’s already gone. This is the sunk cost fallacy at work—a thinking error!” She glared at me as if she had just bitten off a piece of lemon. Okay, I sometimes go overboard on the subject, itself an error called déformation professionnelle. I desperately tried to clarify the situation. “We have spent the thirty dollars regardless of whether we stay or leave, so this factor should not play a role in our decision.” Needless to say, I gave in and sunk back down in my seat.
You are on your way to a concert. At an intersection, you encounter a group of people, all staring at the sky. Without even thinking about it, you peer upward, too. Why? Social proof. In the middle of the concert, when the soloist is displaying absolute mastery, someone begins to clap and suddenly the whole room joins in. You do, too. Why? Social proof. After the concert you go to the coat check to pick up your coat. You watch how the people in front of you place a coin on a plate, even though, officially, the service is included in the ticket price. What do you do? You probably leave a tip as well.
In 1957, Swedish opera singer Friedrich Jorgensen bought a tape player to record his vocals. When he listened back to the recording, he heard strange noises throughout, whispers that sounded like supernatural messages. A few years later, he recorded birdsong. This time, he heard the voice of his deceased mother in the background whispering to him: “Fried, my little Fried, can you hear me? It’s Mammy.” That did it. Jorgensen turned his life around and devoted himself to communicating with the deceased via tape recordings.
As essayist and trader Nassim Taleb resolved to do something about the stubborn extra pounds he’d been carrying, he contemplated taking up various sports. However, joggers seemed scrawny and unhappy, and bodybuilders looked broad and stupid, and cyclists? Oh, so bottom-heavy! Swimmers, though, appealed to him with their well-built, streamlined bodies. He decided to sing up at his local swimming pool and to train hard twice a week.