By measuring inflammation before and after the slide show, the researchers were able to determine whether seeing pictures of disease-y people actually stimulated the immune system to fight infection—and it did! Merely seeing images of people who might be sick triggered white blood cells to mount a vigorous response to bacterial infection. The researchers even found that the immune system was deeply rational about the types of images that set off a biological response. A different group of participants viewed photos of people who looked dangerous. Some of the people in these photos brandished guns pointed right at the camera, thus aimed directly at the participants themselves (these kinds of images trigger the self-protection subself). Although the dangerous pictures were rated as even more distressing than the disease-y pictures, exposure to images of physical danger had no effect on immune system reaction. Only exposure to disease cues prompted the immune system to kick into higher gear.
REVISITING ZAMBIAN AID AND MUTANT FRENCH FRIES
The behavioral immune system produces an array of responses designed to help prevent infection. Some of these responses may initially appear irrational and completely unrelated to disease. For instance, priming the disease-avoidance subself leads people to be more prejudiced against foreigners from exotic places like Sri Lanka and Ethiopia. While this seems a little strange at first blush, it makes much more sense when one considers that strange outsiders have historically been likely to carry diseases foreign to our immune system, making us especially vulnerable. Most of the post-Columbus decline in the Native American population was due merely to coming into contact with diseases carried by the Europeans. The massacre at Wounded Knee was nothing compared to smallpox. Our psychological disease-avoidance system facilitates deeply rational responses by spurring us to avoid contact with anything or anyone that might require a physiologically costly mobilization of our real immune system.
Given what we know about our behavioral immune system, let’s revisit the Zambian food-aid predicament, in which even hungry people refused to eat genetically modified food. When people think about eating genetically modified substances, they often imagine ingesting something physically unnatural, strange, and unknown into their bodies. We want our fruits and vegetables to be “natural.” Labeling them as “genetically modified” conjures up unnatural science fiction images—a disfigured blue potato or a red banana with lumpy outgrowths.
Aid workers were outraged at the Zambian president for rejecting genetically modified food aid, especially because many Americans were already eating genetically modified foods on a daily basis. In 2000, around the time of the Zambian aid fiasco, all french fries served in American McDonald’s restaurants came from genetically modified potatoes. But it turns out that while consumers loved the taste of these super McSpuds, the vast majority were unaware they were eating genetically modified potatoes.
When Americans learned about the true origin of their fries, it sparked a national outrage in the United States not too different from the indignation in Zambia. American citizens insisted that they would only eat “normal” potatoes. It didn’t matter that agricultural inspectors had deemed the genetically modified potatoes perfectly safe. Nor did it make any difference that the World Health Organization has never found ill effects on human health from eating genetically modified foods. Cognitive reasoning has little effect on people when the disease-avoidance subself takes charge. As a result of the protests, McDonald’s had no choice but to switch back to the old “natural” potatoes. In the same way that Zambians refused to ingest genetically modified food, Americans refused to touch mutant french fries.
SEX DETECTORS: IN THE MIND OF MEN’S MATE-ACQUISITION SUBSELVES
Thus far we have focused on ancestral biases geared for successful defense, such as those used by our disease-avoidance subself that protect us from disease. But in the game of natural selection, a good defense is only part of the story. Evolutionary success involves both solving the challenges of danger and disease (having a good defense) and taking advantage of opportunities to make friends, gain status, and reproduce (having a good offense). In fact, a good offense can be even more critical from an evolutionary perspective. If a successfully defensive person lives to be one hundred years old, his genes will die with him unless he can send some of them out on a mating mission. By contrast, the genes of a mediocre defender who only manages to live to age thirty still have a chance as long as he sends some of his genes out on a few successful quests.
Just as animals have detection systems to spot danger and disease, they have other sets of mechanisms to detect opportunities. Take the silkworm moth, known to fluent Latin entomologists as Bombyx mori and to the ancient Chinese as a flying cash crop. When female silkworm moths are interested in mating, they release a chemical called bombykol. The evolutionary success of male moths depends on whether they can detect the presence of an interested female. But there’s a problem: females produce only the tiniest amounts of this sex pheromone. So males have evolved extremely sensitive bombykol detectors, enabling them to detect this chemical in concentrations as low as 1 molecule in 1,000,000,000,000,000,000 air molecules (that’s a quintillion, in case your cash supplies don’t typically require you to count that many zeroes). With that level of sensitivity, a guy moth can detect the scent of a lady moth over ten kilometers away. When it comes to mating, male silkworm moths are like sharks, which can detect a drop of blood in a bay full of water and dart toward their target.
In the same way that evolution has endowed humans with intentionally biased smoke detectors for superb defense, natural selection has also produced intentionally biased sex detectors for conducting a mating offense. Unlike the shrill wail of a smoke detector, which leads us to avoid deadly mistakes, the sound of a sex detector alarm is a pleasant melody, propelling us toward reproductive opportunities. Men, for example, are notorious for making judgment errors when it comes to gauging women’s romantic interest. As many women can attest, men are often delusional—a guy may think a woman is romantically interested in him when nothing could be further from the truth. If an attractive woman does so much as look a man’s way, many men think: She wants me.
In one of our studies, we asked men to look at photos of attractive women. Although the women all had perfectly neutral facial expressions, the men in the study were told that the models were suppressing a specific emotion. The men were told that the point of the study was to see if they could pick up on “microexpressions” in other people’s faces, which might, in this case, leak the true emotions the women were feeling. Before being asked to determine what emotion the women in the photographs might be suppressing, some of the men watched a film clip that elicited romantic feelings—it depicted a highly attractive woman falling for a handsome man. After having his mate-acquisition subself awakened, a typical man believed that he could detect subtle signs of suppressed sexual interest in the attractive women’s expressions. It didn’t matter that these were photos of women that had been preselected for their perfectly neutral, stoic expressions. In a sense, the men were convinced that the beautiful female models were flirting with them.
The mate-acquisition subself has preset men’s sex detectors to be overly sensitive. While this setting leads men to make errors in judgment, it’s an evolutionarily calculated error. This bias is the flip side of the smoke detector principle, which biases judgment to avoid costly errors. Recall that there are two types of errors: misses and false alarms. In the case of men trying to infer female interest, a false alarm means that a man perceives sexual interest when there is none. But a miss means that a man fails to perceive sexual interest when a woman is in fact interested. From an evolutionary perspective, the cost to a man of overlooking a sexual opportunity (a miss) is greater than the cost of occasionally wasting time pursuing a disinterested woman (a false alarm). Because a typical man doesn’t get all that many mating opportunities, it is especially important not to let one slip by.
Natural selection has rigged men’s mate-acquisition subself
to overestimate the extent to which women are interested in them. This might frequently lead men to appear like delusional fools, but evolutionary success in the mating domain is a numbers game—the more you’re willing to ask, the more mates you’re likely to get. In fact, if an average-looking male college student walks up to a female student who is single and asks her out on a date, studies show that he will be successful in scoring a date about 50 percent of the time. Obviously, a guy who thinks a woman is interested in him is more likely to ask her on a date, whereas a guy who guesses she’s uninterested will shy away, even though there is a good chance that she would have said yes. If you’re a guy, you might never get a date unless you’re occasionally willing to make a fool of yourself.
Women, on the other hand, do not show the sexual overperception bias. Instead, they are generally wisely skeptical when it comes to men—though, as we’ll see, not always.
SEXY BAD BOY DELUSIONS: IN THE MIND OF WOMEN’S MATE-ACQUISITION SUBSELVES
Many women believe that a good romantic partner is someone who is reliable, dependable, and will make a good father. Yet many of these same women have their hearts broken after pursuing a man who is charismatic, sexy, adventurous, and hopelessly unreliable—think of the dapper Don Draper on Mad Men or Christian Grey in Fifty Shades of Grey. Whereas dating guides for men teach bachelors how to be the dangerous bad boy women can’t resist, dating guides for women implore them to steer clear of commitment-phobic sexy cads and instead choose the reliable “Mr. Good Enough.” How is it, then, that, despite continuous warnings and recurring heartbreak, some women keep going after the wrong guy?
Recall that women’s shopping behavior and exotic dancing prowess is subconsciously influenced by their ovulatory cycles, which cause women to seek sexier clothing and act in more enticing ways. Ovulation is a hormonal trigger for women’s mate-acquisition subself. And during the few days around ovulation when they are most fertile, women subconsciously become more attracted to the George Clooneys and James Bonds of the world—men who are charming, physically attractive, masculine, and adventurous.
Even though such men are obvious playboys, some women convince themselves that these handsome Don Juans are just the kind of men they can tame and turn into good husbands. Some evolutionary psychologists have argued that natural selection engineered ovulating women to be drawn to these handsome specimens because symmetry, masculinity, and social dominance are biological markers of male genetic fitness. George Clooney’s handsome, masculine appearance might be a signal that he is bearing genes that will make for healthier, stronger, and sexier offspring (kids who will grow up to play both good defense and good offense). But because other women are also likely to throw themselves at these strapping specimens, such men often have a problem with commitment, making them less-than-ideal relationship partners.
Because most women are more interested in long-term commitments than one-night stands, why would they ever think it wise to pursue a relationship with precisely the men who are most likely to cheat, lie, and then leave them for the next woman who comes along?
It turns out that ovulation warps women’s perceptions of sexy bad boys. In one study, ovulating and nonovulating college-age women were introduced to two different men. The women got to know the guys over a videoconferencing system. One of the men (actually an actor) played a convincing role as a reliable “good dad” type: nice, caring, reasonably good-looking, and wanting nothing more than a committed relationship and a family. But despite these desirable characteristics, this nice fellow was also shy, boring, and unsure of himself. A second guy (also a trained actor) was more intriguing: he was a sexy bad boy, a gorgeous hunk with an athletic body and a magnetic charisma. This fellow knew how to take charge and show a woman a good time, but he also sent up all the clear red flags that he was unreliable and undependable.
After they interacted with both guys, the ovulating and nonovulating women rated each of the two bachelors. When they were evaluating the “good dad,” ovulation had no effect. Women thought he seemed pretty sweet but was nothing special, regardless of where they were in their cycle. But when evaluating the sexy bad boy, ovulating women became delusional. Women under the influence of their own natural fertility hormones came to believe that the sexy cad would become a committed and stable relationship partner and that he would magically transform into a dream husband and father—the kind of magical transformation that happens at the climax of almost every women’s romance novel. When their ovulatory hormones were flowing, women deluded themselves into believing that the James Bond type would not only change diapers, cook, and happily give the baby baths but even take on more than half of the parental care! When looking at the sexy bad boy through ovulation goggles, Mr. Wrong looked exactly like Mr. Right.
The research suggests that fertility hormones trigger women’s sex detectors. Rather than being skeptical of a sexy bad boy’s intentions, ovulating women are ready to go on the offensive—by unwittingly allowing themselves to believe that they can transform sexy cads into good husbands and dads. Because natural selection engineered women’s minds to find ways to extract high-quality male genes, this ovulatory delusion may be the extra push some women need to participate in sexual encounters with men high in genetic quality. Occasionally, the right woman does successfully inspire one of these playboy types to settle down—even Brad Pitt was finally persuaded to become a devoted husband and father. Ovulation seems to delude women into thinking that they could be “the one.”
REASON FOR OPTIMISM: IN THE MIND OF YOUR STATUS SUBSELF
We talked earlier about how Steve Jobs partnered up with his buddy Steve Wozniak to start Apple. Jobs is considered by many as one of the most brilliant visionaries of the modern age. Yet few would describe him as having had an accurate grasp of reality. Jobs was notorious for being supremely confident in his own ideas—so confident that those closest to him believed his perception of the objective world was permanently warped by a “reality distortion field.” And this wasn’t just because Jobs had the inflated ego that sometimes comes with great success. As a twenty-three-year-old college dropout in the late 1970s, Jobs already had the gall to show up to corporate meetings barefoot and reeking of body odor. It didn’t matter that he was trying to convince investors to give him millions of dollars; Jobs showered once a week and refused to wear deodorant, certain that his diet of apples rendered it unnecessary. Despite heading a fledgling company without a proven product, Jobs was so convinced of the brilliance of his ideas that he felt corporate investors shouldn’t care at all if he looked and smelled like a vagrant.
A surprising number of people share Jobs’s inclination toward overconfidence. When men are asked to rank themselves on athletic ability, 100 percent of men rate themselves in the top 50 percent. Every first-year MBA student at the University of Chicago expects to receive an above-average grade in his or her first class, even though fully half of them will fail to do so. Psychologists call this the overconfidence bias, and there is no arguing that it is mathematically irrational. It’s simply not possible for everyone to be better than average. But although this bias can lead us to appear foolish and irrational, it may actually be smart when it comes to taking advantage of opportunities to gain status.
Political scientist Dominic Johnson finds evidence that confidence, especially overconfidence, can be an evolutionarily adaptive bias. Confidence is an essential ingredient of success in job performance, sports, and business. While some people presume that confidence makes people lazy and careless, the exact opposite is actually true. Confidence serves to increase ambition, resolve, and persistence. Confident individuals are more likely to remain optimistic and keep on trying in the face of uncertainty. For example, overconfident life insurance agents who view setbacks as mere flukes, rather than accurately viewing them as signs of incompetence, are more likely to persist and eventually sell more policies.
Using sophisticated mathematical models, Johnson and his colleague James Fowler found that overconfide
nce is actually likely to enhance an individual’s evolutionary fitness when competing for resources. This is the domain of our status subself, which is especially prone to the overconfidence bias. Confidence is adaptive because it leads people to approach opportunities and persist in the face of failure rather than sit on their butts and miss out on what could have been. Too much overconfidence can certainly produce arrogance and occasionally lead to very disastrous choices (overconfidence has been blamed for World War I, the Vietnam War, the war in Iraq, and the lack of preparation for many deadly environmental disasters). But being optimistic about our chances of winning is what inspires us to swing the bat and actually hit a home run rather than stand there hoping that something good will happen if we hang around on the bench. Confidence also has a lot to do with getting promotions at work. People who are seen as confident are also seen as more competent. And when it’s time to select a leader, studies find that the top jobs go to people who are seen as competent, regardless of the reality.
The Rational Animal: How Evolution Made Us Smarter Than We Think Page 11
