Why People Believe Weird Things

Pseudoscience, Superstition, and Other Confusions of Our Time

Michael Shermer; Foreword by Stephen Jay Gould

Holt Paperbacks

PART 1
SCIENCE AND SKEPTICISM
Science is founded on the conviction that experience, effort, and reason are valid; magic on the belief that hope cannot fail nor desire deceive.
—Branislaw Malinowski, Magic, Science, and Religion, 1948
1
I Am Therefore I Think
A Skeptic’s Manifesto




On the opening page of his splendid little book To Know a Fly, biologist Vincent Dethier makes this humorous observation about how children grow up to be scientists: “Although small children have taboos against stepping on ants because such actions are said to bring on rain, there has never seemed to be a taboo against pulling off the legs or wings of flies. Most children eventually outgrow this behavior. Those who do not either come to a bad end or become biologists” (1962, p. 2). In their early years, children are knowledge junkies, questioning everything in their purview, though exhibiting little skepticism. Most never learn to distinguish between skepticism and credulity. It took me a long time.
In 1979, unable to land a full-time teaching job, I found work as a writer for a cycling magazine. The first day on the job, I was sent to a press conference held in honor of a man named John Marino who had just ridden his bicycle across America in a record 13 days, 1 hour, 20 minutes. When I asked him how he did it, John told me about special vegetarian diets, megavitamin therapy, fasting, colonies, mud baths, iridology, cytotoxic blood testing, Rolfing, acupressure and acupuncture, chiropractic and massage therapy, negative ions, pyramid power, and a host of weird things with which I was unfamiliar. Being a fairly inquisitive fellow, when I took up cycling as a serious sport I thought I would try these things to see for myself whether they worked. I once fasted for a week on nothing but a strange mixture of water, cayenne pepper, garlic, and lemon. At the end of the week, John and I rode from Irvine to Big Bear Lake and back, some seventy miles each way. About halfway up the mountain I collapsed, violently ill from the concoction. John and I once rode out to a health spa near Lake Elsinore for a mud bath that was supposed to suck the toxins out of my body. My skin was dyed red for a week. I set up a negative ion generator in my bedroom to charge the air to give me more energy. It turned the walls black with dust. I got my iris read by an iridologist, who told me that the little green flecks in my eyes meant something was wrong with my kidneys. To this day my kidneys are functioning fine.
I really got into cycling. I bought a racing bike the day after I met John and entered my first race that weekend. I did my first century ride (100 miles) a month later, and my first double century later that year. I kept trying weird things because I figured I had nothing to lose and, who knows, maybe they would increase performance. I tried colonics because supposedly bad things clog the plumbing and thus decrease digestive efficiency, but all I got was an hour with a hose in a very uncomfortable place. I installed a pyramid in my apartment because it was supposed to focus energy. All I got were strange looks from guests. I starting getting massages, which were thoroughly enjoyable and quite relaxing. Then my massage therapist decided that “deep tissue” massage was best to get lactic acid out of the muscles. That wasn’t so relaxing. One guy massaged me with his feet. That was even less relaxing. I tried Rolfing, which is really deep tissue massage. That was so painful that I never went back.
In 1982 John and I and two other men competed in the first Race Across America, the 3,000-mile, nonstop, transcontinental bike race from Los Angeles to New York. In preparation, we went for cytotoxic blood testing because it was supposed to detect food allergies that cause blood platelets to clump together and block capillaries, thus decreasing blood flow. By now we were a little skeptical of the truth of these various claims, so we sent in one man’s blood under several names. Each sample came back with different food allergies, which told us that there was a problem with their testing, not with our blood. During the race, I slept with an “Electro-Acuscope,” which was to measure my brain waves and put me into an alpha state for better sleeping. It was also supposed to rejuvenate my muscles and heal any injuries. The company swore that it helped Joe Montana win the Super Bowl. Near as I can figure, it was totally ineffective.
The Electro-Acuscope was the idea of my chiropractor. I began visiting a chiropractor not because I needed one but because I had read that energy flows through the spinal cord and can get blocked at various places. I discovered that the more I got adjusted, the more I needed to get adjusted because my neck and back kept going “out.” This went on for a couple of years until I finally quit going altogether, and I’ve never needed a chiropractor since.
All told, I raced as a professional ultra-marathon cyclist for ten years, all the while trying anything and everything (except drugs and steroids) that might improve my performance. As the Race Across America got bigger—it was featured for many years on ABC’s Wide World of Sports—I had many offers to try all sorts of things, which I usually did. From this ten-year experiment with a subject pool of one, I drew two conclusions: nothing increased performance, alleviated pain, or enhanced well-being other than long hours in the saddle, dedication to a consistent training schedule, and a balanced diet; and it pays to be skeptical. But what does it mean to be skeptical?
What Is a Skeptic?
I became a skeptic on Saturday, August 6, 1983, on the long, climbing road to Loveland Pass, Colorado. It was Day 3 of the second Race Across America, and the nutritionist on my support crew believed that if I followed his megavitamin therapy program, I would win the race. He was in a Ph.D. program and was trained as a nutritionist, so I figured he knew what he was doing. Every six hours I would force down a huge handful of assorted vitamins and minerals. Their taste and smell nearly made me sick, and they went right through me, producing what I thought had to be the most expensive and colorful urine in America. After three days of this, I decided that megavitamin therapy, along with colonics, iridology, Rolfing, and all these other alternative, New Age therapies were a bunch of hooey. On that climb up Loveland Pass, I dutifully put the vitamins in my mouth and then spit them out up the road when my nutritionist wasn’t looking. Being skeptical seemed a lot safer than being credulous.
After the race I discovered that the nutritionist’s Ph.D. was to be awarded by a nonaccredited nutrition school and, worse, I was the subject of his doctoral dissertation! Since that time I have noticed about extraordinary claims and New Age beliefs that they tend to attract people on the fringes of academia—people without formal scientific training, credentialed (if at all) by nonaccredited schools, lacking research data to support their claims, and excessively boastful about what their particular elixir can accomplish. This does not automatically disprove all claims made by individuals exhibiting these characteristics, but it would be wise to be especially skeptical when encountering them.
Being skeptical is nothing new, of course. Skepticism dates back 2,500 years to ancient Greece and Plato’s Academy. But Socrates’ quip that “All I know is that I know nothing” doesn’t get us far. Modern skepticism has developed into a science-based movement, beginning with Martin Gardner’s 1952 classic, Fads and Fallacies in the Name of Science. Gardner’s numerous essays and books over the next four decades, such as Science: Good, Bad, and Bogus (1981), The New Age: Notes of a Fringe Watcher (1991a), and On the Wild Side (1992), established a pattern of incredulity about a wide variety of bizarre beliefs. Skepticism joined pop culture through magician James “the Amazing” Randi’s countless psychic challenges and media appearances in the 1970s and 1980s (including thirty-six appearances on the Tonight Show). Philosopher Paul Kurtz helped create dozens of skeptics groups throughout the United States and abroad, and publications such as Skeptic magazine have national and international circulation. Today, a burgeoning group of people calling themselves skeptics—scientists, engineers, physicians, lawyers, professors, teachers, and the intellectually curious from all walks of life—conduct investigations, hold monthly meetings and annual conferences, and provide the media and the general public with natural explanations for apparently supernatural phenomena.
Modern skepticism is embodied in the scientific method, which involves gathering data to test natural explanations for natural phenomena. A claim becomes factual when it is confirmed to such an extent that it would be reasonable to offer temporary agreement. But all facts in science are provisional and subject to challenge, and therefore skepticism is a method leading to provisional conclusions. Some things, such as water dowsing, extrasensory perception, and creationism, have been tested and have failed the tests often enough that we can provisionally conclude that they are false. Other things, such as hypnosis, lie detectors, and vitamin C, have been tested but the results are inconclusive, so we must continue formulating and testing hypotheses until we can reach a provisional conclusion. The key to skepticism is to navigate the treacherous straits between “know nothing” skepticism and “anything goes” credulity by continuously and vigorously applying the methods of science.
The flaw in pure skepticism is that when taken to an extreme, the position itself cannot stand. If you are skeptical about everything, you must be skeptical of your own skepticism. Like the decaying subatomic particle, pure skepticism spins off the viewing screen of our intellectual cloud chamber.
There is also a popular notion that skeptics are closed-minded. Some even call us cynics. In principle, skeptics are not closed-minded or cynical. What I mean by a skeptic is one who questions the validity of a particular claim by calling for evidence to prove or disprove it. In other words, skeptics are from Missouri—the “show me” state. When we hear a fantastic claim, we say, “That’s nice, prove it.”
Here is an example. For many years I had heard stories about the “Hundredth Monkey phenomenon” and was fascinated with the possibility that there might be some sort of collective consciousness that we could tap into to decrease crime, eliminate wars, and generally unite as a single species. In the 1992 presidential election, in fact, one candidate—Dr. John Hagelin from the Natural Law Party—claimed that if elected he would implement a plan that would solve the problems of our inner cities: meditation. Hagelin and others (especially proponents of Transcendental Meditation, or TM) believe that thought can somehow be transferred between people, especially people in a meditative state; if enough people meditate at the same time, some sort of critical mass will be reached, thereby inducing significant planetary change. The Hundredth Monkey phenomenon is commonly cited as empirical proof of this astonishing theory. In the 1950s, so the story goes, Japanese scientists gave monkeys on Koshima Island potatoes. One day one of the monkeys learned to wash the potatoes and then taught the skill to others. When about one hundred monkeys had learned the skill—the so-called critical mass—suddenly all the monkeys knew it, even those on other islands hundreds of miles away. Books about the phenomenon have spread this theory widely in New Age circles. Lyall Watson’s Lifetide (1979) and Ken Keyes’s The Hundredth Monkey (1982), for example, have been through multiple printings and sold millions of copies; Elda Hartley even made a film called The Hundredth Monkey.
As an exercise in skepticism, start by asking whether events really happened as reported. They did not. In 1952, primatologists began providing Japanese macaques with sweet potatoes to keep the monkeys from raiding local farms. One monkey did learn to wash dirt off the sweet potatoes in a stream or the ocean, and other monkeys did learn to imitate the behavior. Now let’s examine Watson’s book more carefully. He admits that “one has to gather the rest of the story from personal anecdotes and bits of folklore among primate researchers, because most of them are still not quite sure what happened. So I am forced to improvise the details.” Watson then speculates that “an unspecified number of monkeys on Koshima were washing sweet potatoes in the sea”—hardly the level of precision one expects. He then makes this statement: “Let us say, for argument’s sake, that the number was ninety-nine and that at 11:00 A.M. on a Tuesday, one further convert was added to the fold in the usual way. But the addition of the hundredth monkey apparently carried the number across some sort of threshold, pushing it through a kind of critical mass.” At this point, says Watson, the habit “seems to have jumped natural barriers and to have appeared spontaneously on other islands” (1979, pp. 2—8).
Let’s stop right there. Scientists do not “improvise” details or make wild guesses from “anecdotes” and “bits of folklore.” In fact, some scientists did record exactly what happened (for example, Baldwin et al. 1980; Imanishi 1983; Kawai 1962). The research began with a troop of twenty monkeys in 1952, and every monkey on the island was carefully observed. By 1962, the troop had increased to fifty-nine monkeys and exactly thirty-six of the fifty-nine monkeys were washing their sweet potatoes. The “sudden” acquisition of the behavior actually took ten years, and the “hundred monkeys” were actually only thirty-six in 1962. Furthermore, we can speculate endlessly about what the monkeys knew, but the fact remains that not all of the monkeys in the troop were exhibiting the washing behavior. The thirty-six monkeys were not a critical mass even at home. And while there are some reports of similar behavior on other islands, the observations were made between 1953 and 1967. It was not sudden, nor was it necessarily connected to Koshima. The monkeys on other islands could have discovered this simple skill themselves, for example, or inhabitants on other islands might have taught them. In any case, not only is there no evidence to support this extraordinary claim, there is not even a real phenomenon to explain.
Science and Skepticism
Skepticism is a vital part of science, which I define as a set of methods designed to describe and interpret observed or inferred phenomena, past or present, and aimed at building a testable body of knowledge open to rejection or confirmation. In other words, science is a specific way of analyzing information with the goal of testing claims. Defining the scientific method is not so simple, as philosopher of science and Nobel laureate Sir Peter Medawar observed: “Ask a scientist what he conceives the scientific method to be and he will adopt an expression that is at once solemn and shifty-eyed: solemn, because he feels he ought to declare an opinion; shifty-eyed, because he is wondering how to conceal the fact that he has no opinion to declare” (1969, p. 11).
A sizable literature exists on the scientific method, but there is little consensus among authors. This does not mean that scientists do not know what they are doing. Doing and explaining may be two different things. However, scientists agree that the following elements are involved in thinking scientifically:

Induction: Forming a hypothesis by drawing general conclusions from existing data.
Deduction: Making specific predictions based on the hypotheses.
Observation: Gathering data, driven by hypotheses that tell us what to look for in nature.
Verification: Testing the predictions against further observations to confirm or falsify the initial hypotheses.

Science, of course, is not this rigid; and no scientist consciously goes through “steps.” The process is a constant interaction of making observations, drawing conclusions, making predictions, and checking them against evidence. And data-gathering observations are not made in a vacuum. The hypotheses shape what sorts of observations you will make of nature, and these hypotheses are themselves shaped by your education, culture, and particular biases as an observer.
This process constitutes the core of what philosophers of science call the hypothetico-deductive method, which, according to the Dictionary of the History of Science, involves “(a) putting forward a hypothesis, (b) conjoining it with a statement of ‘initial conditions,’ (c) deducing from the two a prediction, and (d) finding whether or not the prediction is fulfilled” (Bynum, Browne, and Porter 1981, p. 196). It is not possible to say which came first, the observation or the hypothesis, since the two are inseparably interactive. But additional observations are what flesh out the hypothetico-deductive process, and they serve as the final arbiter on the validity of predictions. As Sir Arthur Stanley Eddington noted, “For the truth of the conclusions of science, observation is the supreme court of appeal” (1958, p. 9). Through the scientific method, we may form the following generalizations:

Hypothesis: A testable statement accounting for a set of observations.
Theory: A well-supported and well-tested hypothesis or set of hypotheses.
Fact: A conclusion confirmed to such an extent that it would be reasonable to offer provisional agreement.

A theory may be contrasted with a construct: a nontestable statement to account for a set of observations. The living organisms on Earth may be accounted for by the statement “God made them” or the statement “They evolved.” The first statement is a construct, the second a theory. Most biologists would even call evolution a fact.
Through the scientific method, we aim for objectivity: basing conclusions on external validation. And we avoid mysticism: basing conclusions on personal insights that elude external validation.
There is nothing wrong with personal insight as a starting point. Many great scientists have attributed their important ideas to insight, intuition, and other mental leaps hard to pin down. Alfred Russel Wallace said that the idea of natural selection “suddenly flashed upon” him during an attack of malaria. But intuitive ideas and mystical insights do not become objective until they are externally validated. As psychologist Richard Hardison explained,

Mystical “truths,” by their nature, must be solely personal, and they can have no possible external validation. Each has equal claim to truth. Tealeaf reading and astrology and Buddhism; each is equally sound or unsound if we judge by the absence of related evidence. This is not intended to disparage any one of the faiths; merely to note the impossibility of verifying their correctness. The mystic is in a paradoxical position. When he seeks external support for his views he must turn to external arguments, and he denies mysticism in the process. External validation is, by definition, impossible for the mystic. (1988, pp. 259—260)

Science leads us toward rationalism: basing conclusions on logic and evidence. For example, how do we know the Earth is round? It is a logical conclusion drawn from observations such as
• The shadow of the Earth on the moon is round.
• The mast of a ship is the last thing seen as it sails into the distance.
• The horizon is curved.
• Photographs from space.
And science helps us avoid dogmatism: basing conclusions on authority rather than logic and evidence. For example, how do we know the Earth is round?
• Our parents told us.
• Our teachers told us.
• Our minister told us.
• Our textbook told us.
Dogmatic conclusions are not necessarily invalid, but they do beg other questions: How did the authorities come by their conclusions? Were they guided by science or some other means?
The Essential Tension Between Skepticism and Credulity
It is important to recognize the fallibility of science and the scientific method. But within this fallibility lies its greatest strength: self-correction. Whether a mistake is made honestly or dishonestly, whether a fraud is unknowingly or knowingly perpetrated, in time it will be flushed out of the system by lack of external verification. The cold fusion fiasco is a classic example of the system’s swift exposure of error.
Because of the importance of this self-correcting feature, among scientists there is at best what Caltech physicist and Nobel laureate Richard Feynman called “a principle of scientific thought that corresponds to a kind of utter honesty—a kind of leaning over backwards.” Said Feynman, “If you’re doing an experiment, you should report everything that you think might make it invalid—not only what you think is right about it: other causes that could possibly explain your results” (1988, p. 247).
Despite these built-in mechanisms, science remains subject to problems and fallacies ranging from inadequate mathematical notation to wishful thinking. But, as philosopher of science Thomas Kuhn (1977) noted, the “essential tension” in science is between total commitment to the status quo and blind pursuit of new ideas. The paradigm shifts and revolutions in science depend upon proper balancing of these opposing impulses. When enough of the scientific community (particularly those in positions of power) are willing to abandon orthodoxy in favor of the (formerly) radical new theory, then and only then can a paradigm shift occur (see chapter 2).
Charles Darwin is a good example of a scientist who negotiated the essential tension between skepticism and credulity. Historian of science Frank Sulloway identifies three characteristics in Darwin’s thinking that helped Darwin find his balance: (1) he respected others’ opinions but was willing to challenge authorities (he intimately understood the theory of special creation, yet he overturned it with his own theory of natural selection); (2) he paid close attention to negative evidence (Darwin included a chapter called “Difficulties on Theory” in the Origin of Species—as a result his opponents could rarely present him with a challenge that he had not already addressed); (3) he generously used the work of others (Darwin’s collected correspondence numbers over 14,000 letters, most of which include lengthy discussions and question-and-answer sequences about scientific problems). Darwin was constantly questioning, always learning, confident enough to formulate original ideas yet modest enough to recognize his own fallibility. “Usually, it is the scientific community as a whole that displays this essential tension between tradition and change,” Sulloway observed, “since most people have a preference for one or the other way of thinking. What is relatively rare in the history of science is to find these contradictory qualities combined in such a successful manner in one individual” (1991, p. 32).
The essential tension in dealing with “weird things” is between being so skeptical that revolutionary ideas pass you by and being so open-minded that flimflam artists take you in. Balance can be found by answering a few basic questions: What is the quality of the evidence for the claim? What are the background and credentials of the person making the claim? Does the thing work as claimed? As I discovered during my personal odyssey in the world of alternative health and fitness therapies and gadgets, often the evidence is weak, the background and credentials of the claimants are questionable, and the therapy or gadget almost never does what it is supposed to.
This last point may well be the crucial one. I regularly receive calls about astrology. Callers usually want to know about the theory behind astrology. They are wondering whether the alignment of planetary bodies can significantly influence human destiny. The answer is no, but the more important point is that one need not understand gravity and the laws governing the motion of the planets to evaluate astrology. All one needs to do is ask, Does it work? That is, do astrologers accurately and specifically predict human destiny from the alignment of the planets? No, they do not. Not one astrologer predicted the crash of TWA flight #800; not one astrologer predicted the Northridge earthquake. Thus, the theory behind astrology is irrelevant, because astrology simply does not do what astrologers claim it can do. It vanishes hand-in-hand with the hundredth monkey.
The Tool of the Mind
Vincent Dethier, in his discussion of the rewards of science, runs through a pantheon of the obvious ones—money, security, honor—as well as the transcendent: “a passport to the world, a feeling of belonging to one race, a feeling that transcends political boundaries and ideologies, religions, and languages.” But he brushes all these aside for one “more lofty and more subtle”—the natural curiosity of humans:

One of the characteristics that sets man apart from all the other animals (and animal he indubitably is) is a need for knowledge for its own sake. Many animals are curious, but in them curiosity is a facet of adaptation. Man has a hunger to know. And to many a man, being endowed with the capacity to know, he has a duty to know. All knowledge, however small, however irrelevant to progress and well-being, is a part of the whole. It is of this the scientist partakes. To know the fly is to share a bit in the sublimity of Knowledge. That is the challenge and the joy of science. (1962, pp. 118-119)

At its most basic level, curiosity about how things work is what science is all about. As Feynman observed, “I’ve been caught, so to speak—like someone who was given something wonderful when he was a child, and he’s always looking for it again. I’m always looking, like a child, for the wonders I know I’m going to find—maybe not every time, but every once in a while” (1988, p. 16). The most important question in education, then, is this: What tools are children given to help them explore, enjoy, and understand the world? Of the various tools taught in school, science and thinking skeptically about all claims should be near the top.
Children are born with the ability to perceive cause-effect relations. Our brains are natural machines for piecing together events that may be related and for solving problems that require our attention. We can envision an ancient hominid from Africa chipping and grinding and shaping a rock into a sharp tool for carving up a large mammalian carcass. Or perhaps we can imagine the first individual who discovered that knocking flint would create a spark that would light a fire. The wheel, the lever, the bow and arrow, the plow—inventions intended to allow us to shape our environment rather than be shaped by it—started us down a path that led to our modern scientific and technological world.
On the most basic level, we must think to remain alive. To think is the most essential human characteristic. Over three centuries ago, the French mathematician and philosopher René Descartes, after one of the most thorough and skeptical purges in intellectual history, concluded that he knew one thing for certain: “Cogito ergo sum—I think therefore I am.” But to be human is to think. To reverse Descartes, “Sum ergo cogito—I am therefore I think.”
Copyright © 1997, 2002 by Michael Shermer