The Neurons of Recovery

By Wray Herbert

One of the cornerstones of many addiction treatment programs is what’s called “moral inventory.” Rather than just white-knuckling it through day after miserable day without drugs or alcohol, recovering addicts and alcoholics are taught to honestly and rigorously monitor their daily thoughts and behavior and relationships, and when they do something wrong to promptly set things right. The idea is that personal dishonesty is somehow related to destructive habits, and that authenticity in daily life is a key to staying clean and sober.

Just how this happens is a mystery, and most recovering addicts don’t much care about the details. But psychologists are very interested in the spiritual dimensions of sobriety. How can
daily vigilance and small ethical acts—apologizing for being hurtful or rude or uncharitable—translate into the concrete choice not to light up a crack pipe or pour a tumbler of whiskey? What could such moral striving possibly have to do with the tormenting compulsions of addiction?

New brain research may help illuminate this mystery. Psychologist Rebecca Compton of Haverford College and her colleagues have been observing the vigilant brain in action, and exploring the connection between cognitive watchfulness and serenity. They don’t use a spiritual vocabulary, of course. In the jargon of the laboratory, they have been studying “error-related negativity,” or ERN. This is shorthand for an electrical pulse that comes from particular region of the brain, a bundle of neurons known to watch out for mistakes. They have also been studying a separate but nearby part of the brain responsible for correcting errors once they’re spotted. They wanted to see if and how these basic tools of cognitive regulation relate to stress and anxiety in the real world.

Here’s how they set up the experiment. They had college students volunteer to take an exceptionally difficult version of the Stroop Test. You’re probably familiar with this test, because it circulates on the Internet as a kind of parlor game: The names of colors appear on the screen in various colors, and you’re required very rapidly to name the color of the ink—rather than read the word. So the word R-E-D might appear in green, and you have to punch green. It’s very difficult to do, because you have to override the brain’s impulse to read the word. But difficulty is precisely what the psychologists were aiming for, because they wanted the volunteers to make a lot of mistakes.

The volunteers were wired to an EEG while they were taking the Stroop Test, so the researchers could record their ERN pulses. They were in effect gauging how vigilant they were, how much of their brain power they were using to spot errors. At the same time, they measured their speed and accuracy in the test—basically to see how readily they corrected course after detecting a mistake.

Then they sent the volunteers home. But before they did, they asked them to keep a journal of their trials and tribulations and emotional life for a couple weeks. Every night before they went to bed, they assessed the day: Were they under deadline pressure that day? Did they feel overwhelmed by responsibilities? Was there too much to do today, and too little time? That kind of thing. They also kept track of their moods—whether they were anxious or calm or worried or relaxed.

Then they crunched all the data together, with interesting results. As they describe in the July issue of the journal Psychological Science, participants varied both in their levels of vigilance and in their ability to learn from their mistakes. That in itself is not all that surprising, but here’s the interesting part: Those with overall greater cognitive control—the ones who monitored themselves closely and adjusted efficiently—were also the ones who were best at handling stress. Remember that these were college students, so almost all of them felt pressures from deadlines and too much work. But the ones who spotted and corrected errors in their own mental performance were in general more calm and relaxed, even with college life’s predictable stresses. The ones who did not inventory and learn from their mistakes were beaten down by life’s pressures.

Why would this be? It’s not entirely clear, but Compton and her colleagues believe it’s because mental regulation and emotional regulation draw on the same set of skills, perhaps even powered by some common neurons. People who are quick to spot their own slip-ups and quick to fix them are the same people who are good at keeping their emotions in tow when hit by life’s travails. In colloquial language, that’s called not sweating the small stuff. In the language of addiction recovery, it’s often called serenity, or emotional sobriety, and the path there does indeed seem to begin with a simple moral statement: “Oops, I made a mistake.”

For more insights into the quirks of human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman. Selections from the weblog also appear in the magazine Scientific American Mind and at http://www.sciam.com/.

You've Got to Feel the Zero

By Wray Herbert

I work out in the gym just about every morning, but I can’t say that I’m always eager to get started. I’m basically lazy, and exercise is hard. Many days I would much rather linger over a second mug of coffee and browse the newspapers. But I don’t, because I have made a bargain with the universe.

The bargain is simple: I pay a small price for a big payoff later, in good health and well being. I know there are no money-back guarantees, but it’s a wager I’m willing to make. People strike similar deals all the time. We choose years of hard work and poverty to go to college and graduate school, banking on later gratification, or we forego this winter’s tropical vacation to save for retirement.

Or we don’t. Lots of people see these as bad deals, and would rather take the money and run, live for today. Why is that? How can some of us see a particular tradeoff as advantageous, while others of us see precisely the same deal as foolish? Psychologists are very interested in this question, as are policy makers, who see the huge social costs of impulsive decision making.

One theory is that some people are simply not as good at forecasting the future. If something is way off in the distance, it’s very difficult to keep its importance front and center in the mind. So we discount it, literally. But is it possible to think about such tradeoffs differently, in a way that might help us delay our immediate rewards for a better deal later on?

Stanford University psychologists Eran Magen, Carol Dweck and James Gross decided to explore this in the lab. Specifically, they wondered if the way a tradeoff is “framed” in the mind might affect whether or not we choose an immediate but small payoff over a greater reward later on. For example, you probably think of a tradeoff as two competing options: You can have $5 right now, or $6.20 in a month. By framing it this way, you focus on the difference between $5 and $6.20, which is $1.20. That’s a lot less than the immediate $5, which has a lot of emotional pull. So it’s easy to understand why a lot of people might go for it.

But what if you conceptualized the tradeoff in a very different way, focusing on the passing of time? Picture yourself on one of those moving walkways, going through life. Every so often, someone hands you an envelope, which contains your wages in cash. You could still take that $5 now, but that’s not the end of the deal; time keeps moving, and a month later someone hands you another envelope. You open it expectantly and . . . nada, zero, zip. And you were expecting a raise to boot. Think about the disappointment.

That’s the real choice you have in life, and that empty envelope makes all the difference. The details of the tradeoff haven’t changed. The empty envelope was there all along, but it was hidden. That is, choosing between $5 and $6.20 suggests two payoffs frozen in time. But life is a continuum, and in reality there are two paydays, one of which must be a big zero. Projecting yourself forward to the day of the greater disappointment may be enough to make you opt for less disappointment today.

At least that’s the theory, which the psychologists tested on the Internet and describe in the July issue of the journal Psychological Science. They had participants choose between immediate and delayed payments in a variety of scenarios, varying the amounts of money and the time interval that separated now and the future. Sometimes the tradeoff was stated as: $5 now or $6.20 later. Other times it was: $5 now and $0 later OR $0 now and $6.20 later. Invariably, when the zero-dollar payday was spelled out, rather than hidden, the subjects were less impulsive in their choices. Put another way, they didn’t like the notion of opening that empty envelope, even off in the future, and it nudged them toward a more rational weighing of the options.

So what does this have to do with exercise and health? Say you blow off the gym and linger over coffee, or get another hour’s sleep—whatever. That’s like taking your $5 now. But it’s harder to enjoy as much when you know that the walkway is still moving. And somewhere down the line there is an empty envelope with your name on it.

For more insights into the quirks of human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman. Selections from this weblog now appear in the magazine Scientific American Mind and at http://www.sciam.com/.

Polling the Crowd Within

By Wray Herbert

Imagine you’re a contestant on the TV trivia show Who Wants To Be a Millionaire? You’re poised to win a cool $32,000, but you’re stumped and annoyed. Who cares which country is the largest exporter of grapes? You could use your 50-50 "life line," which asks the computer to narrow the choices from four to two. But this is unlikely to help, because more often than not the computer deletes the two answers you’ve already ruled out on your own. You could use your “Phone-a-Friend” option, which means ringing your father at home. He’s sitting there with a pile of reference books waiting for your call. But he’s only got 30 seconds, and how would you look that up anyway? You can already imagine his resigned voice saying: “I’m really sorry, Mary. I’m afraid I just don’t know.”

But there’s a third option: You canuse your “Ask-the-Audience" life line. You can poll the entire studio audience on the four possible answers, and their responses are instantaneously assembled into a bar graph. Invariably, this graph shows one overwhelming choice, and with rare exceptions the audience is right. “I’ll trust the audience,” you tell Regis. “Final answer.”

Good move. But why? No person in the audience is any more likely than you to know where grapes come from, yet the collective intelligence of the group is almost always a better bet than your best guess. Psychologists are very interested in this perplexing statistical phenomenon. If the crowd is always wiser than any individual, what does that say about the way knowledge is stored and arranged in our minds? And can it help us make better choices, even beyond game shows?

Psychologists Edward Vul of MIT and Harold Pashler of the University of California in San Diego decided to explore these questions in the laboratory. More specifically, they wondered if perhaps each of us carries around in our mind a “crowd”—with a range of knowledge like that of any real life crowd. If so, they reasoned, then it should be possible to get a more accurate answer by asking ourselves the same question more than once, and averaging the responses.

To test this idea, the psychologists created their own Internet quiz show. They asked participants a variety of questions about trivia, not unlike the questions one might get on Who Wants To Be a Millionaire: For example, “What percentage of the world’s airports are in the United States?” But then they asked some of the contestants to answer the same questions again, immediately. Others were asked three weeks later to answer the same questions. The idea was to sample the range of answers within an individual mind, and to see if the range changed over time. It seems logical that one’s first answer should exhaust a person’s best knowledge about the world’s airports, but what if that’s not true? What if each of us has a whole range of possible answers to that trivia question, and the best guess lies in the middle somewhere?

That’s actually what Vul and Pashler found when they ran the experiment. As reported in the July issue of the journal Psychological Science, the average of two guesses for any individual participant was better than either guess alone, regardless of the time between guesses. So polling the “crowd within” does indeed yield a statistically more accurate answer. What’s more, this internal crowd gets more independent-minded with time: Contestants who were asked to second-guess themselves three weeks later benefited even more by averaging their two guesses than did those who second-guessed themselves immediately. The psychologists speculate that the cognitive pull of the original answer loses its power and allows more mental flexibility over time. In other words, the researchers say, there may be some science behind the folk wisdom: “Sleep on it.”

But no individual contestant did as well as a large group. That is, second-guessing oneself always yielded an answer that was better than the first, but it was still a sampling of one mind—and no match for the wisdom of the collective mind. For that, it appears, your best option really is to ask the audience. In the real world, that’s called vox populi.


For more insights into the quirks of human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman. Selections from this weblog now appear in each issue of Scientific American Mind and on http://www.sciam.com/.

Primed For Ripeness

By Wray Herbert

There was a time when the world was full of women named Daisy and Iris and Lily and Rose. Naming daughters after nature’s blooms was considered a high compliment, a celebration of feminine beauty. Flowery names aren’t in fashion so much these days, but the tradition of linking blossoms and womanhood runs long and deep. Just think back on the romantic imagery of Shakespeare or Burns or Keats.

The tradition may go back even further than that as it turns out, way back before poetry and language, and indeed may be deep-wired into our neurons. Some psychologists are now suggesting that the association between blooming flowers and womanhood may have ancient evolutionary roots, indeed that our liking for sprays of heather and violets may be the vestige of a long-lost survival skill: the ability to spot a good sexual partner. What’s more, this primordial connection may explain all sorts of modern human preferences that are completely unrelated to sexuality or mating.

Here’s the basic idea. When our ancient ancestors were first becoming human, the key to the species’ survival was sexual “fitness.” That is, primitive humans had to find strategies to produce hardy offspring, who then did the same, and on and on. One of these primitive strategies was an ability to select, from all the possible mates, the most healthy and fertile. Put another way, early humans became hypersensitive to signs of ripeness, and this hypersensitivity became deeply engrained in our perception and thinking and emotion, where it remains today.

What happens with these primitive skills, though, is that they are blunt instruments. They don’t discriminate well, so that a cognitive shortcut that was intended for mate selection is also applied to other living things—apples, for example, or greyhounds or marigolds. So today we retain a hard-wired bias that makes us favor any living thing at its peak, and to disfavor anything that’s unripe or in decline.

At least that’s the theory, which Yale University psychologists Julie Huang and John Bargh decided to test in the laboratory. They designed a series of experiments to see if, by piquing the fundamental human desire to mate, they could increase people’s sensitivity to a variety of cues to immaturity, growth, peak ripeness, and decay.

Here’s an example from their lab. The psychologists had a group of volunteers, all young adults, read a passage from the book See Jane Date, by Melissa Senate. This book is apparently a classic of “chick lit,” focusing on the lives of unmarried but nubile young women, and it was intended to jump-start the readers’ mating instinct. Another comparable group of volunteers read a bland passage describing the interior of a building.

Then they had both groups look at four photographs of the actress Jane Withers, each from a different stage of her long acting career. Some may remember Jane Withers as “Josephine the Plumber,” in the TV ads for the cleanser Comet, in the 1960s, but she actually began acting in the 1930s as an adorable toddler, and also played roles as a teen and as a leading lady. The photos showed all of these stages of her life.

The volunteers were then asked to rate the four images in terms of the actress’s appeal. The idea was that those with mating on their mind would find the actress much more appealing in her prime, and devalue her when she was either older or sexually immature. And that’s exactly what they found. Those who had not been primed for sex showed no strong preferences for prime years over youth or later years.

So this supports the evolutionary link between the “ripeness bias” and tastes in human beauty. But does the bias go beyond humans? To test this, Huang and Bargh modified the experiment a bit. They again primed some of the volunteers with the passage from See Jane Date, but this time they had them look at photographs of bananas. Some of the bananas were green, some yellow-green, some completely yellow, and some mottled with brown spots. All the volunteers then rated the attractiveness of the fruit.

I know what you’re thinking. Yes, most of us prefer yellow bananas to either green or brown bananas. They generally taste better and have better texture. But what the psychologists were measuring was the difference between volunteers who had been primed for mating and those who had not. And they did find a big difference in their preference for perfectly ripe bananas and for bananas before or after their peak.

So it really does seem that people are primed for ripeness. But for those who remain skeptical, the psychologists decided to check this notion one more way. There were no automobiles on the savannahs three million years ago; not even carts. So if the theory is sound, these same fundamental preferences for peak age over newness and senescence should apply only to living things, not artifacts. The psychologists ran one more experiment, basically the same as the other two, but in this one they had the volunteers rate photos of flowers and cars. They predicted that they would have maturity-related preferences when it came to flowers, but not when it came to cars.

An automobile’s peak, for this study, was when the car rolled off the assembly line, spanking new. Other photos showed the car under construction or beginning to rust with age. The flowers went from bud to full flowering to wilting. And the scientists found just what they expected. That is, being primed for mating did shape people’s preference for blooming flowers, but it had no effect on their preferences for the life stages of a car. We may not like to see our trusty old cars rust out, but it apparently has no deep psychological resonance.

These findings, reported in the June issue of Psychological Science, may go way beyond our preferences for floral imagery and women’s names, the authors conclude. Think of a completely unrelated social domain, like the workplace. If these age-related biases really do run so deep, and are so easily activated, might they have an effect on, say, our judgments of career ability? Ageism may have deeper roots than we know.

For other insights into the quirks of human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman. A version of this blog now appears in the magazine Scientific American Mind and the website http://www.sciam.com/.

The Neurology of Stereotypes

By Wray Herbert

I once attended a polytechnic school where the mascot was an engineer. It was a men’s school, so the image of the mascot was a kind of geeky looking guy. He wore a goofy hat and was always surveying land or harnessing electrical power or some such. It was an unflattering caricature, and meant to be funny in a self-deprecating kind of way.

A lot of students and alumni didn’t like it, though, and the engineer was eventually replaced with a bird. That’s the problem with stereotypes: They contain enough truth to be both humorous and cruel. We all use stereotypes, probably more than we’d care to admit, because they are fast and efficient cognitive shortcuts that save us a lot of time and energy. You probably have a caricature of an engineer in your mind’s eye right now.

Psychologists are very interested in stereotypes, and how the brain processes them. Do we know when we are falling back on a broad caricature, or do we use them automatically, without deliberation or conscious awareness? How do we police our own lazy mental habits to avoid harming others with simplistic stereotypical thinking? Do we know that stereotypes are wrong, yet find them too psychologically tempting to avoid?

Psychologist Wim De Neys of Leuven University, Belgium, decided that the best way to explore these questions was to actually look at the brain in action. Past research has shown that a particular region of the brain’s frontal lobe becomes active when we detect conflict in our thinking—between an easy stereotype, say, and a more reasoned and complex view. But actually overriding stereotypical thinking requires another part of the frontal lobe. De Neys basically wanted see if stereotypical thinking is a detection problem or a self-control problem. To see, he watched these two brain regions during stereotypical thinking, to see what lit up.

He used a classic psychology problem to make people summon up the stereotypes residing in their neurons. Here’s how it works: Say there’s a room with 1000 people in it, and we know that 995 are lawyers and the other five are engineers. We get to meet just one of these people, named Jack, picked randomly from the group. We learn that Jack is 45-years-old and has four children. He has little interest in politics or social issues and is generally conservative. He likes sailing and mathematical puzzles. Is Jack a lawyer, or an engineer?

Well, which is he? Logically, if you use the statistical part of your brain only, the obvious answer is that he’s a lawyer, simply because there are all those lawyers in the room and there’s a better chance of meeting a lawyer in the room than an engineer. But a lot of people immediately say engineer because Jack fits a stereotype. The majority of even highly educated people do this. Others do say lawyer—and so quickly that it seems instantaneous—but the question is whether the brain needs to quash that powerful engineer caricature in order to give the more reasoned response.

De Neys watched volunteers’ brains as they puzzled through this and similar problems. He found (and describes in the May issue of the journal Psychological Science) that the brain’s stereotype detector lit up regardless of whether the subject answered stereotypically or rationally. So apparently we all detect the stereotype and recognize that it is out of sync with reality. But the brain’s inhibition center—the part of the brain that says, “No, I am not falling for that simplistic idea”—lit up only when the subjects actually reasoned that Jack was a lawyer—that is, only when they overrode the stereotype and made a calculation based on probability. Apparently some of us find the ready caricatures too tempting and use them anyway, against our better judgment.

This goes way beyond fairness to engineers. Think about another stereotype, this one the typical lung cancer victim. He’s old, right? That’s at least the stereotype that most teenagers have, and the one they use to justify taking up smoking. Young people don’t die of lung cancer, so smoking must not be risky for the young—all scientific evidence to the contrary notwithstanding. Stereotypes can indeed be cruel and hurtful—even to those who conjure them up.

For more insights into the quirks of human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman. This blog now also appears in both the print and web editions of Scientific American Mind at www.sciam.com.

The Gist of the Matter

By Wray Herbert

I had a brief stint teaching writing and rhetoric to college freshmen, and I tried to pass on to my students a valued lesson a favorite professor had given me. Nuance is good; generalities are facile. Be wary of any thinker who thinks in black or white, insists on yes or no, or argues without gradation or grayness or subtlety. God is in the details.

I guess I still believe that. But I’ll have to say that the intervening years of parenting have given me an appreciation for some plain and absolute values: AIDS, bad. Seat belts, good. Heroin, bad. And so forth. I’m not really interested in discussing the subtleties of these positions. Am I getting more rigid as I get older?

Well, maybe I am, but that may not be an entirely bad thing. Recent psychological research suggests that our brains are like hybrid engines, switching back and forth between two very different kinds of thinking. Sometimes we crunch data and painstakingly calculate choices and positions, and sometimes we rapidly and automatically seize on the essence, the simple value, the gist of the matter. And how we think determines in large part the decisions we make. The trick is in knowing when to do which.

Teenagers are not very good at this, as it turns out, with sometimes tragic consequences. Consider this recent experiment by three Cornell University psychologists. Britain Mills, Valerie Reyna and Steven Estrada used a laboratory manipulation to trigger either precise, quantitative thinking or unnuanced “gist thinking” in a large sample of high school students. Then they studied their actual life choices, and their intentions for the near future. The topic was sex and its risks, including pregnancy and diseases like syphilis and AIDS.

Here’s an example of the triggers that the psychologists used. Sometimes they asked a specific question, like: “Are you likely to get pregnant or get someone pregnant in the next six months?” Other times they asked very general questions, like: “Overall, for you, which of the following best describes the risks of having sex: low, medium or high?” The idea here is that precise questions trigger precise memories—actual literal memories of past experiences—and that recalling these specific events jumpstarts the brain process devoted to fine-grain analysis: They start actually weighing risks and benefits, and when they do that, they often end up rationalizing “acceptable risk.” The global questions, by contrast, summon up simple values and qualitative thinking, like: “Risk, bad. Avoid risk.”

They also asked the teenagers to say yes or no to statements like these: “Less risk is better than more risk” and “No risk is better than some risk.” The idea was to sort out the absolute thinkers from the relativists, on the theory that any thinking about relative risk puts the brain into analytic mode, which in turn leads (paradoxically) to increased risk-taking.

And paradoxical or not, that is exactly what the scientists found. They subsequently asked all the students not only if they had had sex already, but also the specifics of what they were planning on: sex within the coming year, sex before age 20, and so forth. As reported in the May issue of the journal Psychological Science, the teenagers who weighed the relative risks and benefits of sex were much more likely to actually have sex (or plan on it) than were those who thought in global ways about risk and peril. Put another way, simple absolute values were protective. Too much data crunching was not. Or to borrow a newer version of the old maxim: “The devil’s in the details.”

For more insights into the quirks of human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman.

A Deadly Philosophy

By Wray Herbert

Humans are the only species that systematically murders its own for ideological reasons. More than 50 million people were victims of mass murder in the 20th century, making it the deadliest century on record. That included the Ottoman Turks’ murder of 1.5 million Armenians, the Nazis’ extermination of six million Jews, Mao’s murder of 30 million Chinese, and the Khmer Rouge’s destruction of 1.7 million Cambodians. The list goes on.*

Some of these deaths had to do with land and water and such, but most did not. Most were over philosophy. Why would this be? Philosophy is not threatening in any literal sense; it can’t maim or make you die, even when it’s very different from your view. Psychologists are very interested in this paradox: Why is philosophy—or worldview, or ideology—so threatening? Put another way, what are the cognitive and emotional underpinnings of mass murder and genocide?

One emerging theory suggests that genocide may make sense, at least on an emotional level. Think of it this way. Besides being the only animal to murder on principle, humans are also the only animal cognitively advanced enough to understand mortality. We all know we are going to die, and there is absolutely nothing we can do to prevent this. That fact should be utterly terrifying, so terrifying that we should be paralyzed by fear and trembling.

But we’re not. We get up every morning, dress and groom ourselves, go to work, play with the kids, and so forth. How do we manage this? Well, one way we manage is by constructing meaning, and we do that by imagining a meaningful world. That’s called philosophy—or religion, or whatever. Humans are meaning-making creatures.

The problem occurs when our carefully constructed philosophy is threatened. And the greatest threat to a belief system is, well, an alternative belief system. To put it bluntly, your unfamiliar worldview makes me keenly aware of my mortality; it threatens my very existence. So why shouldn’t I wish you dead? Philosophy is personal.

Scientists have actually been studying this entanglement of personal mortality and cultural hatred in the lab, with some interesting results. Here’s a recent experiment by Joseph Hayes and his colleagues at the University of Alberta, Canada. These psychologists wanted to explore whether a philosophical threat could indeed conjure up thoughts of death, and further whether those thoughts might be quelled by actual annihilation of the philosophical “enemy.” To explore this, they recruited devout Christians for an experiment. They had these Christians read an actual news story about the “Muslimization of Nazareth”: The article described how Jesus’s birthplace had become largely a Muslim city, and how the dominant (and militant) Muslim population was marginalizing the Christians who remained.

The idea was that this unwelcome news about a holy Christian landmark would threaten the Christian readers’ worldview—and in turn their personal security. And indeed it appears it did. After they had read about Nazareth, they all took a psychological test that gauges preoccupation with thoughts of death and dying. As reported in the May issue of the journal Psychological Science, those who had read the report were much more morbid in their imagery than those who had not. They were also much more derogatory toward Muslims than were Christians who had not read the news.

So that’s pretty unsettling in itself. But here’s where it gets really interesting. Hayes and his colleagues then told half of the participants another bit of news, only in this case it was made up. They told them that an airplane had crashed on its way to Nazareth, killing all 117 devout Muslims aboard. When they crunched the data, they found that those who had “witnessed” the annihilation of the Muslims were significantly less morbid in their thinking and significantly less derogatory toward Muslims. Put another way, knowing of the violent death of the Muslims effectively undid the perceived threat to the Christians’ philosophy and well-being. It restored meaning and security to their lives.

Isn't it possible that the plane crash simply made the Christians more sympathetic toward the Muslims, at least temporarily? The psychologists actually considered and rejected this idea, based on a surprising finding. The Christians who read about Nazareth became increasingly negative not only toward Muslims, but also toward Buddhists and Hindus and atheists. That is, they became antagonistic toward any worldview that questioned the absolute validity of Christianity. What's more, those who read the fabricated story about the plane crash were less disparaging of all these worldviews. Since no Hindus or Buddhists or atheists perished in the crash, there would be no reason for the Christians to feel sympathy toward these people.

So our brain fights death with death. It reasons that if an enemy dies, his philosophy must have been perverse or weak or just plain wrong, and thus no real threat to our superior worldview—nor to our life and limb. It’s a powerful psychological defense. In real life, of course, it just raises the ante. It’s tit for tat, and the new century starts counting its genocide victims.

*For a thorough examination of 20th century genocide, see Lewis Simons’s “Genocide and the Science of Proof” in the January 2006 issue of National Geographic magazine.

For more insights into human nature, visit “We’re Only Human . . .” at www.psychologicalscience.org/onlyhuman.