An old yarn about a classic marketing con game on the secret of wealth instructs you to write a book about how to make a lot of money and sell it through the mail. When your marks receive the book, they discover the secret — write a book about how to make a lot of money and sell it through the mail.

A confidence scheme similar to this can be found in The Secret (Simon & Schuster, 2006), a book and DVD by Rhonda Byrne and a cadre of self-help gurus that, thanks to Oprah Winfrey’s endorsement, have now sold more than three million copies combined. The secret is the so-called law of attraction. Like attracts like. Positive thoughts sally forth from your body as magnetic energy, then return in the form of whatever it was you were thinking about. Such as money. “The only reason any person does not have enough money is because they are blocking money from coming to them with their thoughts,” we are told. Damn those poor Kenyans. If only they weren’t such pessimistic sourpusses. The film’s promotional trailer is filled with such vainglorious money mantras as “Everything I touch turns to gold,” “I am a money magnet,” and, my favorite, “There is more money being printed for me right now.” Where? Kinko’s?

A pantheon of shiny, happy people assures viewers that The Secret is grounded in science: “It has been proven scientifically that a positive thought is hundreds of times more powerful than a negative thought.” No, it hasn’t. “Our physiology creates disease to give us feedback, to let us know we have an imbalanced perspective, and we’re not loving and we’re not grateful.” Those ungrateful cancer patients. “You’ve got enough power in your body to illuminate a whole city for nearly a week.” Sure, if you convert your body’s hydrogen into energy through nuclear fission. “Thoughts are sending out that magnetic signal that is drawing the parallel back to you.” But in magnets, opposites attract — positive is attracted to negative. “Every thought has a frequency … If you are thinking that thought over and over again you are emitting that frequency.”

The brain does produce electrical activity from the ion currents flowing among neurons during synaptic transmission, and in accordance with Maxwell’s equations any electric current produces a magnetic field. But as neuroscientist Russell A. Poldrack of the University of California, Los Angeles, explained to me, these fields are minuscule and can be measured only by using an extremely sensitive superconducting quantum interference device (SQUID) in a room heavily shielded against outside magnetic sources. Plus, remember the inverse square law: the intensity of an energy wave radiating from a source is inversely proportional to the square of the distance from that source. An object twice as far away from the source of energy as another object of the same size receives only onefourth the energy that the closer object receives. The brain’s magnetic field of 10^–15 teslas quickly dissipates from the skull and is promptly swamped by other magneticsources, not to mention the earth’s magnetic field of 10^–5 teslas, which overpowers it by 10 orders of magnitude!

Ceteris paribus, it is undoubtedly better to think positive thoughts than negative ones. But in the real world, all other things are never equal, no matter how sanguine your outlook. Just ask the survivors of Auschwitz. If the law of attraction is true, then the Jews—along with the butchered Turkish-Armenians, the raped Nanking Chinese, the massacred Native Americans and the enslaved African-Americans — had it coming. The latter exemplar is especially poignant given Oprah’s backing of The Secret on her Web site: “The energy you put into the world — both good and bad — is exactly what comes back to you. This means you create the circumstances of your life with the choices you make every day.” Africans created the circumstances for Europeans to enslave them?

Oprah, please, withdraw your support of this risible twaddle — as you did when you discovered that James Frey’s memoir was a million little lies — and tell your vast following that prosperity comes from a good dollop of hard work and creative thinking, the way you did it.

Among athletes who obsess about their weight, we cyclists are second to none. Training rides are filled with conversations about weight lost or gained and the latest diet regimens and food fads. Resolutions are made and broken. We all know the formula: 10 pounds of extra weight on a 5 percent grade slows your ascent by half a mile an hour. It has a ring of Newtonian finality to it. F = MA. The Force needed to turn the pedals equals Acceleration times that Mass on the saddle.

But most of the guys I ride with are like me: in their 40s and 50s with jobs and families, long past racing prime. We ride because it is fun, and it feels good to be fit. So why obsess over a few pounds? Because that is the cycling culture — emblematic of our society at large — that carries its own internal calculus: the amount of guilt is directly proportional to the rise in the quantity and tastiness of the food.

The problem is that our bodies have evolved to crave copious amounts of rich and tasty foods, because historically such foods were valuable and rare. How can we modern humans resist? We shouldn’t, at least not entirely, says Barry Glassner, a University of Southern California sociologist and author of the forthcoming book, The Gospel of Food: Everything You Think You Know about Food Is Wrong (Ecco). We have wrongly embraced what Glassner calls “the gospel of naught,” the view that “the worth of a meal lies principally in what it lacks. The less sugar, salt, fat, calories, carbs, preservatives, additives, or other suspect stuff, the better the meal.” The science behind this culinary religion, Glassner says, is close to naught.

When it comes to healthy absorption of nutrients, taste matters. Glassner cites a study in which “Swedish and Thai women were fed a Thai dish that the Swedes found overly spicy. The Thai women, who liked the dish, absorbed more iron from the meal. When the researchers reversed the experiment and served hamburger, potatoes and beans, the Swedes, who like this food, absorbed more iron. Most telling was a third variation of the experiment, in which both the Swedes and the Thais were given food that was high in nutrients but consisted of a sticky, savorless paste. In this case, neither group absorbed much iron.”

Speaking of iron, Atkins is out and meat is bad, right? Wrong. Glassner notes a study showing that as meat consumption and blood cholesterol levels increased in groups of Greeks, Italians and Japanese, their death rates from heart disease decreased. Of course, many other variables are involved in determining causal relations between diet and health. Glassner cites a study showing a 28 percent decrease in risk of heart attacks among nonsmokers who exercised 30 minutes a day, consumed fish, fiber and folate, and avoided saturated and trans fats and glucose-spiking carbs. And according to Harvard University epidemiologist Karin Michels, “it appears more important to increase the number of healthy foods regularly consumed than to reduce the number of less healthy foods regularly consumed.” It’s more complicated still. Glassner reviews research showing that heart disease, cancer and other illnesses are significantly increased by “viral and bacterial infections,
job stress, living in distressed neighborhoods, early deficits such as malnutrition, low birth weight, lack of parental support, and chronic sleep loss during adolescence and adulthood.” Another study found that such diseases “are higher in states where participation in civic life is low, racial prejudice is high, or a large gap exists between the incomes of the rich
and poor and of women and men.”

To clarify this cornucopia of data, Glassner quotes the former editor of the New England Journal of Medicine, Marcia Angell: “Although we would all like to believe that changes in diet or lifestyle can greatly improve our health, the likelihood is that, with a few exceptions such as smoking cessation, many if not most such changes will produce only small effects. And the effects may not be consistent. A diet that is harmful to one person may be consumed with impunity by another.”

As the preacher said in Ecclesiastes 8:15: “Then I commended mirth, because a man hath no better thing under the sun, than to eat, and to drink, and to be merry.”

In 2002 I served as the “phone a friend” for the popular television series Who Wants to Be a Millionaire. When my acquaintance was stumped by a question, however, he elected to “poll the audience” instead. His choice was wise not only because I did not know the answer but because the data show that the audience is right 91 percent of the time, compared with only 65 percent for “experts.”

Although this difference may in part be because the audience is usually queried for easier questions, something deeper is at work here. For solving a surprisingly large and varied number of problems, crowds are smarter than individuals. This is contrary to what the 19th-century Scottish journalist Charles Mackay concluded in his 1841 book, Extraordinary Popular Delusions and the Madness of Crowds, a staple of skeptical literature: “Men, it has been well said, think in herds. It will be seen that they go mad in herds, while they only recover their senses slowly, and one by one.” This has been the dogma ever since, supported by sociologists such as Gustave Le Bon, in his classic work The Crowd: A Study of the Popular Mind: “In crowds it is stupidity and not mother wit that is accumulated.”

Au contraire, Monsieur Le Bon. There is now overwhelming evidence, artfully accumulated and articulated by New Yorker columnist James Surowiecki in his enthralling 2004 book, The Wisdom of Crowds (Doubleday), that “the many are smarter than the few.” In one experiment, participants were asked to estimate the number of jelly beans in a jar. The group average was 871, only 2.5 percent off the actual figure of 850. Only one of the 56 subjects was closer. The reason is that in a group, individual errors on either side of the true figure cancel each other out.

A similar result was discovered in an example so counterintuitive that it startles. When the U.S. submarine Scorpion disappeared in May 1968, a naval scientist named John Craven assembled a diverse group of submarine experts, mathematicians and salvage divers. Instead of putting them in a room to consult one another, he had each of them give a best guesstimate — based on the sub’s last known speed and position (and nothing else) — of the cause of its demise and its rate and steepness of descent, among other variables. Craven then computed a group average employing Bayes’s theorem, a statistical method wherein a probability is assigned to each component of a problem. The Scorpion’s location on the ocean floor was only 220 yards from the averaged prediction.

Stranger still was the stock market’s reaction on January 28, 1986, the day the space shuttle Challenger exploded. Of the four major shuttle contractors — Lockheed, Rockwell International, Martin Marietta and Morton Thiokol — the last (the builder of the defective solidrocket booster) was hit hardest, with a 12 percent loss, compared with only 3 percent for the others.

A detailed study of the market (a sizable crowd, indeed!) by economists Michael T. Maloney of Clemson University and J. Harold Mulherin of Claremont McKenna College could find no evidence of insider trading or media focus on the rocket booster or on Morton Thiokol. Given four possibilities, the masses voted correctly.

Not all crowds are wise, of course — lynch mobs come to mind. And “herding” can be a problem when the members of a group think uniformly in the wrong direction. The stock market erred after the space shuttle Columbia disaster on February 1, 2003, for example, dumping stock in the booster’s manufacturer even though the boosters were not involved.

For a group to be smart, it should be autonomous, decentralized and cognitively diverse, which the committee that rejected the foam-impact theory of the space shuttle Columbia while it was still in flight was not. In comparison, Google is brilliant because it uses an algorithm that ranks Web pages by the number of links to them, with those links themselves valued by the number of links to their page of origin. This system works because the Internet is the largest autonomous, decentralized and diverse crowd in history, IMHO.