How We Know What Isn't So (2 page)

Although an examination of these cognitive biases is enormously helpful in understanding questionable and erroneous beliefs, the richness and diversity of such beliefs require a consideration of other factors as well. Accordingly, Part II contains three chapters on the “Motivational and social determinants of questionable beliefs.” Chapter 5 locates the roots of erroneous belief in wishful thinking and self-serving distortions of reality. This chapter provides a revisionist interpretation of motivational effects by examining how our motives collude with our cognitive processes to produce erroneous, but self-serving, beliefs. Chapter 6 examines the pitfalls of secondhand information and the distortions introduced by communicators—including the mass media—who are obliged to summarize and tempted to entertain. Chapter 7 takes a psychological truism, “we tend to believe what we think others believe” and turns it around: We tend to think others believe what we believe. This chapter examines a set of cognitive, social, and motivational processes that prompt us to overestimate the extent to which others share our beliefs, further bolstering our credulity.

Part III adopts a case study approach by bringing all the mechanisms introduced in Parts I and II together in an attempt to understand the origins and durability of several widely held but empirically dubious beliefs. These include beliefs in the efficacy of untested or ineffective health practices (Chapter 8), in the effectiveness of self-defeating interpersonal strategies (Chapter 9), and in the existence of ESP (Chapter 10). These chapters necessarily tread more lightly at times, for it cannot always be said with certainty that the beliefs under examination are false. Nevertheless, there is a notable gap in all cases between belief and evidence, and it is this gap that these chapters seek to explain.

Part IV ends the book with a discussion of how we might improve the way we evaluate the evidence of everyday life, and thus how we can steer clear of erroneous beliefs.

It is a great discredit to humankind that a species as magnificant as the rhinoceros can be so endangered. Their numbers thinned by the encroachment of civilization in the first half of this century, they now face the menace of deliberate slaughter. In the last 15 years, 90% of the rhinos in Africa have been killed by poachers who sell their horns on the black market. The horns fetch a high price in the Far East where they are used, in powdered form, to reduce fevers, cure headaches, and (less commonly) increase sexual potency. As a consequence of this senseless killing, there are now only a few thousand black rhinos left in Africa, and even fewer in Asia and Indonesia.
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Unhappily, the rhinoceros is not alone in this plight. Six hundred black bears were killed in the Great Smoky Mountains during the last three years, their gall bladders exported to Korea where they are thought to be an effective aid for indigestion (bears, the logic runs, are omnivores and are rarely seen to be ill). To understand the severity of this slaughter, it should be noted that the entire bear population in the Great Smoky Mountains at any one time is estimated to be approximately six hundred. A recent raid of a single black-market warehouse in San Francisco uncovered 40,000 seal penises that were to be sold, predictably, for use as aphrodisiacs. The Chinese green-haired turtle has been trapped to near extinction, in part because the Taiwanese believe that it can cure cancer. The list of species that have been slaughtered in the service of human superstition could go on and on.
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I mention these depressing facts to provide an unconventional answer to the familiar questions of “What’s wrong with a few questionable beliefs?” or “Why worry about a little superstition?” This senseless killing makes it clear that the costs of our superstitions are real and severe, and that they are paid for not only by ourselves but by others—including other species. That our mistaken beliefs about aphrodisiacs and cancer cures have brought a number of species to the brink of extinction should challenge our own species to do better—to insist on clearer thinking and the effort required to obtain more valid beliefs about the world. “A little superstition” is a luxury we should not be allowed and can ill afford.

Of course, there are other, more conventional answers to this question of what is wrong with having a few questionable beliefs, answers that focus more on the costs to the believers themselves. The most striking are those cases we all hear about from time to time in which someone dies because a demonstrably effective medical treatment was ignored in favor of some quack therapy. Consider the fate of 7 year-old Rhea Sullins.
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Her father was once president of the American Natural Hygiene Society, which advocates “natural” cures such as fasting and the consumption of fruit and vegetable juices in lieu of drugs and other conventional treatments. When Rhea became ill, her father put her on a water-only fast for 18 days and then on a diet of fruit juice for 17 more. She died of malnutrition at the end of this regimen. I trust the reader has read about a number of similar cases elsewhere. Is there anything more pitiful than a life lost in the service of some unsound belief? As the tragedies of people like Rhea Sullins make clear, there are undeniable benefits in perceiving and understanding the world accurately, and terrible costs in tolerating mistakes.

There is still another, less direct price we pay when we tolerate flawed thinking and superstitious belief. It is the familiar problem of the slippery slope: How do we prevent the occasional acceptance of faulty reasoning and erroneous beliefs from influencing our habits of thought more generally? Thinking straight about the world is a precious and difficult process that must be carefully nurtured. By attempting to turn our critical intelligence off and on at will, we risk losing it altogether, and thus jeopardize our ability to see the world clearly. Furthermore, by failing to fully develop our critical faculties, we become susceptible to the arguments and exhortations of those with other than benign intentions. In the words of Stephen Jay Gould, “When people learn no tools of judgment and merely follow their hopes, the seeds of political manipulation are sown.”
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As individuals and as a society, we should be less accepting of superstition and sloppy thinking, and should strive to develop those “habits of mind” that promote a more accurate view of the world.

I
n 1677, Baruch Spinoza wrote his famous words, “Nature abhors a vacuum,” to describe a host of physical phenomena. Three hundred years later, it seems that his statement applies as well to human nature, for it too abhors a vacuum. We are predisposed to see order, pattern, and meaning in the world, and we find randomness, chaos, and meaninglessness unsatisfying. Human nature abhors a lack of predictability and the absence of meaning. As a consequence, we tend to “see” order where there is none, and we spot meaningful patterns where only the vagaries of chance are operating.

People look at the irregularities of heavenly bodies and see a face on the surface of the moon or a series of canals on Mars. Parents listen to their teenagers’ music backwards and claim to hear Satanic messages in the chaotic waves of noise that are produced.
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While praying for his critically ill son, a man looks at the wood grain on the hospital room door and claims to see the face of Jesus; hundreds now visit the clinic each year and confirm the miraculous likeness.
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Gamblers claim that they experience hot and cold streaks in random rolls of the dice, and they alter their bets accordingly.

The more one thinks about Spinoza’s phrase, the better it fits as a description of human nature. Nature does not “abhor” a vacuum in the sense of “to loathe” or “to regard with extreme repugnance” (Webster’s definition). Nature has no rooting interest. The same is largely true of human nature as well. Often we impose order even when there is no motive to do so. We do not “want” to see a man in the moon. We do not profit from the illusion. We just see it.

The tendency to impute order to ambiguous stimuli is simply built into the cognitive machinery we use to apprehend the world. It may have been bred into us through evolution because of its general adaptiveness: We can capitalize on ordered phenomena in ways that we cannot on those that are random. The predisposition to detect patterns and make connections is what leads to discovery and advance. The problem, however, is that the tendency is so strong and so automatic that we sometimes detect coherence even when it does not exist.

This touches on a theme that will be raised repeatedly in this book. Many of the mechanisms that distort our judgments stem from basic cognitive processes that are usually quite helpful in accurately perceiving and understanding the world. The structuring and ordering of stimuli is no exception. Ignaz Semmelweis detected a pattern in the occurrence of childbed fever among women who were assisted in giving birth by doctors who had just finished a dissection. His observation led to the practice of antisepsis. Charles Darwin saw order in the distribution of different species of finches in the Galapagos, and his insight furthered his thinking about evolution and natural selection.

Clearly, the tendency to look for order and to spot patterns is enormously helpful, particularly when we subject whatever hunches it generates to further, more rigorous test (as both Semmelweis and Darwin did, for example). Many times, however, we treat the products of this tendency not as hypotheses, but as established facts. The predisposition to impose order can be so automatic and so unchecked that we often end up believing in the existence of phenomena that just aren’t there.

To get a better sense of how our structuring of events can go awry, it is helpful to take a closer look at a specific example. The example comes from the world of sports, but the reader who is not a sports fan need not dismay. The example is easy to follow even if one knows nothing about sports, and the lessons it conveys are quite general.

I must caution the reader not to construe the sentences above as two distinct quotations, the first a statement about confidence, and the second an anti-imperialist slogan. Known as Lloyd Free before legally changing his first name, World B. Free is a professional basketball player. His statement captures a belief held by nearly everyone who plays or watches the sport of basketball, a belief in a phenomenon known as the “hot hand.” The term refers to the putative tendency for success (and failure) in basketball to be self-promoting or self-sustaining. After making a couple of shots, players are thought to become relaxed, to feel confident, and to “get in a groove” such that subsequent success becomes more likely. In contrast, after missing several shots a player is considered to have “gone cold” and is thought to become tense, hesitant, and less likely to make his next few shots.

The belief in the hot hand, then, is really one version of a wider conviction that “success breeds success” and “failure breeds failure” in many walks of life. In certain areas it surely does. Financial success promotes further financial success because one’s initial good fortune provides more capital with which to wheel and deal. Success in the art world promotes further success because it earns an artist a reputation that exerts a powerful influence over people’s judgments of inherently ambiguous stimuli. However, there are other areas—gambling games immediately come to mind—where the belief may be just as strongly held, but where the phenomenon simply does not exist. What about the game of basketball? Does success in this sport tend to be self-promoting?

My colleagues and I have conducted a series of studies to answer this question.
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The first step, as always, involved translating the idea of the hot hand into a testable hypothesis. If a player’s performance is subject to periods of hot and cold shooting, then he should be more likely to make a shot after making his previous shot (or previous several shots) than after missing his previous shot. This implies, in turn, that a player’s hits (and misses) should cluster together more than one would expect by chance. We interviewed 100 knowledgeable basketball fans to determine whether this constitutes an appropriate interpretation of what people mean by the hot hand. Their responses indicated that it does: 91% thought that a player has “a better chance of making a shot after having just made his last two or three shots than he does after having just missed his last two or three shots.” In fact, when asked to consider a hypothetical player who makes 50% of his shots, they estimated that his shooting percentage would be 61% “after having just made a shot,” and 42% “after having just missed a shot.” Finally, 84% of the respondents thought that “it is important to pass the ball to someone who has just made several shots in a row.”

To find out whether players actually shoot in streaks, we obtained the shooting records of the Philadelphia 76ers during the 198081 season. (The 76ers are the only team, we were told, who keep records of the
order
in which a player’s hits and misses occurred, rather than simple cumulative totals.) We then analyzed these data to determine whether players’ hits tended to cluster together more than one would expect by chance.
Table 2.1
presents the relevant data. Contrary to the expectations expressed by our sample of fans, players were not more likely to make a shot after making their last one, two, or three shots than after missing their last one, two, or three shots. In fact, there was a slight tendency for players to shoot better after missing their last shot. They made 51% of their shots after making their previous shot, compared to 54% after missing their previous shot; 50% after making their previous two shots, compared to 53% after
missing
their previous two; 46% after making three in a row, compared to 56% after missing three in a row. These data flatly contradict the notion that “success breeds success” in basketball and that hits tend to follow hits and misses tend to follow misses.