The Common Belief Fallacy

Transcription

1 The Common Belief Fallacy THE MISCONCEPTION: The larger the consensus, the more likely it is correct. THE TRUTH: A belief is not more likely to be accurate just because many people share it. Back when Shakespeare said you were the paragon of animals, both noble in reason and infinite in faculties, he did so during a time when physicians believed the body was filled with black bile, yellow bile, phlegm, and blood, and all sickness and health depended on the interaction of those fluids. Lethargic and lazy? Well, that's because you are full of phlegm. Feeling sick? Maybe you've got too much blood and should go see a barber to get drained. The creator of some of the greatest works of the English language believe you could cure a fever with a knife. In your own time, you may have felt some satisfaction, while sitting in a jet, that your species had mastered flight, but it is important to note that the first powered airplane took off in a country in which women weren't allowed to vote, and a lot of people believed they never should. You might gaze upon distant galaxies and marvel at how in less than sixty years your people went from airplanes to spaceships, but in between that time it also fought two world wars and attended a depressing number of child beauty pageants. A lot of people have believed a lot of things that people don't anymore. Belief is a pretty fragile thing, which is probably why most people guard it so carefully. Still, compared to your loinclothed cousins from antiquity, you live in an amazing time. You probably carry a supercomputer in your pocket, and unlike most of your ancestors, you'll probably never worry about food or shelter. You don't go to sleep at night wondering if you'll wake up in a lion's mouth. Looking at things in this way, compared to your ancestors, you might count yourself among the modern geniuses of contemporary society. Not so fast. If this afternoon you were zapped back to medieval times and found yourself standing ankle-deep in mud within a bustling village, what would you be able to offer the people of that time from the future? The advances of science and medicine, the technological leaps and bounds-- how much of that could you impart to an eager alchemist or inquisitive pyromancer? Even if you were an engineer or a chemist, you couldn't just go out and create a Roomba from scratch. You would probably be digging graves or tending livestock within in a week. It's unlikely you would invent the cotton gin or the steam engine. You certainly wouldn't be curing many diseases, either. The best you could probably offer them would be your knowledge of the benefits of sanitation. You see, a lot of what you presume to be evidence of your intelligence is just part of a vast cultural inheritance. If some sort of Reset button were pressed on your slow crawl out of the Stone Age, you would see that you are not much different from people ten

2 thousand years ago. If the planet became a smoldering postnuclear wasteland, what skills and knowledge could you offer the survivors? How much of modern life do you actually understand? My friend Susannah Gregg was living in South Korea and working there as an English teacher when she first learned about fan death, a common belief among people in that country that oscillating desk fans are among the most deadly inventions known to man. She was stepping out for a beer with a friend when he noticed, to his horror, she had left her fan running with her pet rabbit still inside her house. Her friend, a twenty-eight-year-old college graduate, refused to leave until she turned off the fan. He explained to her that everyone knows you can't leave a fan running inside a room with the windows shut. That would mean certain death. It was shocking to him that she was unaware of something so simple and potentially life-threatening. Susannah thought he was kidding. It took several conversations to convince him it wasn't true and that in her country, in most countries, no one believed such a thing. She successfully avoided the common belief fallacy not because she was smarter than her friend but because she had already done the experiments necessary to disprove the myth. She had slept in a house with a fan running many times and lived to tell about it. Since, then, she has asked many friends and coworkers there about fans, and the response has been mixed. Some people think it is silly, and some think fan death is real. Despite the debunking power of a few Google searches, the belief that you shouldn't fall asleep or spend too much time in a room with a running electric fan is so pervasive in South Korea that Susannah told me you can't buy one within their borders without a safety device that turns it off after a set amount of time. The common belief is so deep and strong that fan manufacturers must include a safety switch to soothe the irrational fears of most consumers. The people who thought the world rested on the back of a great tortoise, or the thought dancing would make it rain--they had the same brain as you; that is to say, they had the same blueprint in their DNA for making brains. So a baby born into their world was the same as one born into yours. Evolution is so low that not enough has changed in the ways brains are made to tell the difference between you and a person from ten thousand years ago. Yet when we look back on the ancients, it's easy to laugh at their silly assumptions. From gods to burning chariots to elves making cookies in trees, you ancestors believed in all sorts of things, thanks to the same faulty reasoning you deal with today. In addition, they, too, were fueled by a desire to make sense of reality and to answer the age-old question: "What, exactly, is happening here?" Instead of letting that questions hang in the air, your distant relatives tended to go ahead and answer it, and they kept answering it over and over again, with newer yet equally dumb ideas. One of the most profoundly difficult obstacles humans have faced since we started chipping away at flint to make heads for spears is a malfunction of the mind called the common belief fallacy. In Latin, it is argumentum ad populum, or "appeal to the people," which should clue you in that this is something your species has

3 worried about for a long time. The fallacy works like this: If most people believe something is true, you are more likely to believe it is true the first time you hear about it. You then pass along that mistaken belief, and on and on it goes. Being a social creature, the first thing you do in a new job, new school, new country, or any other novel situation is ask people who are familiar with the environment to help you get acquainted with the best way to do things, the best places to eat, the hand gestures that might get you beheaded, etc. The problem, of course, is that your info is now based on opinions that are based on things such as conformity and emotions and norms and popularity, and if you've spent any time in a high school, on a disco floor, or a rave, you know that what is popular is not always what is good or true. It isn't exactly something we've overcome, but at least we now have a strategy for dealing with it. Before we had a method for examining reality, the truth was a slippery fish, which is why your ancestors were so dumb. I'm not just talking about the ones who banged rocks together, but all of them, even the physicians and philosophers. So dumb, in fact, that for a very long time people got smarter in a slow, meandering, and unreliable sort of way until human beings finally invented and adopted a tool with which to dig their way out of the giant hole of stupid into which they kept falling. The hole here is a metaphor for self-delusion. Your great-great-greatgrandparents didn't really keep falling into giant holes, at least not in numbers large enough to justify a chapter on the topic. The tool here is also a metaphor. I'm talking about the scientific method. Your ancestors invented the scientific method because the common belief fallacy renders your default strategies for making sense of the world generally awful and prone to error. Why do bees like flowers? What causes snow? Where do babies come from? Every explanation in every tribe, city, and nation was as good as the next, even if it was completely made up. Even worse, once an explanation was woven into a culture, it would often become the official explanation for many lifetimes. "What is thunder?" a child might have asked. "Oh, that's the giant snow crab in the sky falling off his bed," a shaman would have explained, and that would have been good enough for everything until they had their own kids and eventually died of dysentery. That hamster wheel of limited knowledge kept spinning until the scientific method caught on. Even then, there was a long way to go and lots of cobwebs to be cleared from common sense. Before formalized science, some very smart people believed in some really weird things. At about the same time Johann Sebastian Bach was composing symphonies, many scientists asserted that "phlogiston" resided within everything you could burn, and once you set it on fire, the phlogiston escaped into the air. If you had some burning wood in a pot and placed a lid over it, the flame would go out because the air could hold only so much phlogiston before it was saturated. Left in the omiren, a piece of wood eventually turned to ash and was, as they put it, fully dephlogisticated. This idea lasted for about a hundred years before it was debunked

4 by diligent scientific attacks. Eventually, scientists realized there was no such thing as phlogiston, and the real magic element was oxygen. Flames consumed oxygen, and lids starved flames. Scholars also used to believe that life just sort of happened sometimes. Learned people going all the way back to Aristotle truly believed that if you left meat outside long enough it would spontaneously generate new life in the form of maggots and flies. The same people thought that if you piled up dirty rags and left them alone for a while they would magically turn into mice. Seriously. The idea started to fade in 1668 when a physician named Francesco Redi tested the hypothesis by placing meat and eggs in both sealed and unsealed containers didn't spontaneously generate life, and thus the concept began to die. Other thinkers contested to put the idea away forever some two centuries later. Many look to experiments and others during that time in human history as a turning point. An upside-down way of looking at the world was making life better. Some say this meat-in-a-bottle business was the real birth of the scientific method. This was proof that looking for disconfirming evidence was a better way to conduct research than proceeding from common belief. Your natural tendency is to start from a conclusion and work backward to confirm your assumptions, but the scientific method drives down the wrong side of the road and tries to disconfirm your assumptions. If you eliminate your suspicions the outline of the truth begins to emerge. Once your forefathers and foremothers realized that this approach generated results, in a few generations your species went from burning witches and drinking mercury to mapping the human genome and playing golf on the moon. Even after your relatives had the scientific method, people still pursued and believed in really weird things, and many old ideas died hard deaths. It's hard to believe, but even simple things such as washing your hands to prevent infection weren't fully accepted by the medical community until relatively recently on the human timeline. Even after it was discovered and documented that washing hands drastically reduced deadly fevers, the idea took a while to catch on. It was just too revolutionary, too weird. The ideas of germs and microscopic organisms challenged a variety of other ideas, including that the source of disease was probably linked to things that stank, which was sort of true when you thought about it. In a world that had already invented the telephone and the lightbulb, hand washing to prevent sickness met enough resistance that doctors argued about it for decades. The twisting path to becoming less dumb has led to many stops and starts, yet humans persist. You may have noticed something wonderful about all these examples--science no longer believes in any of them, and neither do you. In battling the common belief fallacy, new common beliefs themselves are born. That's because science does something for you that you don't do very well on your own. Science continuously tears apart its models of reality looking for weakness. Sure, scientists are just people, prone to the same silliness as anyone else, but the enterprise, the

5 process, slowly but surely grinds away human weakness. It is a self-correcting system that is always closer to the truth today than it was yesterday. When it comes to the common belief fallacy in your own life, remember that scientists are always trying to reach better conclusions, and that is something you don't do as an individual, at least not by default, and by extension is it something your institutions are not so great at either. You don't seek out what science calls the null hypothesis. That is, when you believe in something, you rarely seek out evidence to the contrary to see how it matches up with your assumptions. That's the source of urban legends, folklore, superstitions, and all the rest. Skepticism is not your strong suit. Corporations and other institutions rarely set aside a division tasked with paying attention to the faults of the agency. Unlike the science, most human endeavors leave out a special department devoted to looking for the worst in the operation--not just a complaint department, but also a department that asks if the organization is on the right path. Every human effort should systematically pause and ask if it is currently mistaken. To be less dumb, you need that department constantly operating in your cranium. You should do well to borrow from the lessons of the scientific method and apply them in your personal life. In the background, while you crochet and golf and browse cat videos, science is fighting against your stupidity. No other human enterprise is fighting as hard, or at least not fighting and winning. The people who came before you invented science because your natural ways of understanding and explaining what you experience is terrible. When you have zero evidence, every assumption is basically equal. You prefer to see causes rather than effects, signals in the noise, patterns in the randomness. You prefer easy-tounderstand stories, and thus turn everything in life into a narrative so that complicated problems become easy. Scientists work to remove the narrative, to boil it away, leaving behind only the raw facts. Those data sit there naked and exposed so they can be reflected upon and rearranged by each new visitor. Scientists and laypeople will conjure up new stories using the data, and they will argue, but the data will not budge. They may not even make sense for a hundred years or more, but thanks to the scientific method, the stories, full of biases and fallacies, will crash against the facts and recede into history.