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.
Social proof, sometimes roughly termed the “herd instinct,” dictates that individuals feel they are behaving correctly when they act the same as other people. In other words, the more people who follow a certain idea, the better (truer) we deem the idea to be. And the more people who display a certain behavior, the more appropriate this behavior is judged by others. This is, of course, absurd.
Social proof is the evil behind bubbles and stock market panic. It exists in fashion, management techniques, hobbies, religion, and diets. It can paralyze whole cultures, such as when sects commit collective suicide.
A simple experiment, carried out in the 1950s by legendary psychologist Solomon Asch, shows how peer pressure can warp common sense. A subject is shown a line drawn on paper, and next to it three lines—numbered 1, 2, and 3—one shorter, one longer, and one the same length as the original one. He or she must indicate which of the three lines corresponds to the original one. If the person is alone in the room, he gives correct answers because the task is really quite simple. Now five other people enter the room; they are all actors, which the subject does not know. One after another, they give wrong answers, saying “number 1,” although it’s very clear that number 3 is the correct answer. Then it is the subject’s turn again. In one-third of cases, he will answer incorrectly to match the other people’s responses.
Why do we act like this? Well, in the past, following others was a good survival strategy. Suppose that fifty thousand years ago you were traveling around the Serengeti with your hunter-gatherer friends, and suddenly they all bolted. What would you have done? Would you have stayed put, scratching your head, and weighing up whether what you were looking at was a lion or something that just looked like a lion but was in fact a harmless animal that could serve as a great protein source? No, you would have sprinted after your friends. Later on, when you were safe, you could have reflected on what had actually happened. Those who acted differently—and I am sure there were some—exited the gene pool. We are the direct heirs of those who copied the others’ behavior. This pattern is so deeply rooted in us that we still use it today, even when it offers no survival advantage. Only a few cases come to mind where social proof is of value. For example, if you find yourself hungry in a foreign city and don’t know a good restaurant, it makes sense to pick the one that’s full of locals. In other words, you copy the locals’ behavior.
Comedy and talk shows make use of social proof by inserting canned laughter at strategic spots, inciting the audience to laugh along. One of the most impressive, though troubling, cases of this phenomenon is the famous speech by Nazi propaganda minister Joseph Goebbels, delivered to a large audience in 1943. (See it for yourself on YouTube.) As the war went from bad to worse for Germany, he demanded to know: “Do you want total war? If necessary, do you want a war more total and radical than anything that we can even imagine today?” The crowd roared. If the attendees had been asked individually and anonymously, it is likely that nobody would have consented to this crazy proposal.
The advertising industry benefits greatly from our weakness for social proof. This works well when a situation is unclear (such as deciding among various car makes, cleaning products, beauty products, and so on, with no obvious advantages or disadvantages), and where people “like you and me” appear.
So be skeptical whenever a company claims its product is better because it is “the most popular.” How is a product better simply because it sells the most units? And remember English novelist W. Somerset Maugham’s wise words: “If fifty million people say something foolish, it is still foolish.”