Last Ape Standing: The Seven-Million-Year Story of How and Why We Survived (23 page)
Read Last Ape Standing: The Seven-Million-Year Story of How and Why We Survived Online
Authors: Chip Walter
Tags: #Science, #Non-Fiction, #History
What makes so many of these evolutionary traits intriguing is how extravagant they are. They don’t seem to serve any practical purpose, not at first glance. In fact they can sometimes get in the way of survival because they require enormous strength, extra stores of nutrition, or draw the attention of predators. Biologists call these costly attention getters “fitness indicators” because they are billboards that mostly male animals use to advertise to females the fabulous genes they are toting around. Extravagant dances, battles with other males, wildly orchestrated warbling, gargantuan antlers, luminous bottoms, thick manes—all of these are powerful, but costly, signals to the opposite sex. Their sole purpose is to prove “I am the man!”
Like other animals, we humans have evolved an impressive variety of fitness indicators too. Modern human women, for example, have
breasts much larger than those of any other primate, yet their expanded size serves no apparent practical purpose. Female gorillas and chimpanzees have small breasts and nurse their offspring just fine. But for humans, full, round breasts subconsciously signal health and fertility. (The original meaning of the word
buxom
was healthy and easygoing, not large breasted.)
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The same is true for rounder rumps and a clearly defined hourglass figure. Several studies have revealed that men of nearly every culture are attracted to women whose waists are about 70 percent of the size of their hips. Other studies have shown that a certain amount of fat on the backsides and hips of women is a universal signal of fertility. Because of the subtle messages they send, over time evolution favored women with these traits for the simple reason that they were terrifically accurate indicators of health. Their offspring then tended to survive and go on to mate and pass the health–enhancing genes along.
Women seek out fitness indicators in men, too. They find slim hips and broad shoulders attractive because physical strength sends subliminal messages that such a man is not only a fertile source of firstrate DNA, but athletic enough to survive the dangers of the world and bring home the bacon.
The importance of fitness indicators has even driven the way we look. The human face is one of the best advertisers of health in nature, which is why we are so tuned in to beauty and handsomeness. We love symmetry in the countenances of others, not to mention bright smiles, white teeth, smooth skin, and thick hair. Many of us assume that we develop our attraction to these traits because we learn it. That’s partly true. Fashion trends and hairstyles can affect what we consider beautiful as Darwin’s research illustrated, but our tastes in physical beauty are almost entirely primal and subconscious, which is to say, they are not learned.
Psychologist Judith Langlois at the University of Texas, Austin, for example, has found these tendencies are so deep that even infants prefer comely caregivers to unlovely ones. She and her research team figured this out by gathering together the odd combination of sixty babies, one woman, and an expert mask–maker. For the experiment the team asked the mask–maker to fit two masks to a female caretaker—one that made her look pretty, the other not so pretty. This woman
was a stranger to all the babies, and the masks were extremely realistic, a skin over the caregiver’s real skin that smiled or frowned and moved seamlessly no matter how she expressed herself. To ensure that the woman didn’t act differently depending on what sort of mask she was wearing—something that might subtly have affected the babies’ behavior—the caregiver herself was never allowed to know whether the mask she was wearing made her appear handsome or unsightly. Only the babies knew.
Once she was properly disguised, the woman then began play with each of the sixty babies in turn. Their playing was tightly scripted to keep the experience for each child consistent. Every play date was captured on videotape, and low and behold, the study revealed that the infants, according to Langlois, “more frequently avoided the woman when she was unattractive than when she was attractive, and they showed more negative emotion and distress in the unattractive than in the attractive condition. Furthermore, boys (but not girls) approached the female stranger more often in the attractive rather than in the unattractive condition, perhaps foreshadowing the types of interactions that may later occur at parties and other social situations when the boys are older!”
Other studies reinforce the primal depth of our preference for beauty in one another. College students have been shown to prefer cuter babies to less cute ones, even when they initially said all babies look alike, and mothers have even been shown to act more attentively and affectionately toward firstborns who were considered attractive than to those who weren’t. Grade–school children who are good–looking are treated better by their peers than their less attractive counterparts, and another Langlois experiment illustrated that babies no older than six months of age looked longer at pictures of attractive adults, no matter what their race or ethnic background.
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None of these experiments means that any of this behavior makes sense. In fact it is proof that it doesn’t because the world is, regrettably, filled with attractive people who are neither kind, nor trustworthy, nor particularly intelligent, all useful traits in a human. Nothing about beauty makes it innately good or bad, and we have thankfully evolved the mental capacity to understand that. Nevertheless, we have a difficult time resisting the primal impulses that
cause us to prefer physical attractiveness because it has proven over time to be a spectacularly strong indicator of a personal gene pool that endows its owner with a better chance of making it from one day to the next. It may not be as useful an indicator today as it once was, but millions of years or evolution creates habits that are wickedly difficult to shake.
Why does any of this matter? Because that childhood–extending phenomenon we call neoteny and our universal preference for beauty are profoundly bound to one another, even if it isn’t immediately obvious. Together they help explain why the countenance you sleepily gaze at in the mirror each morning looks more like an infant ape’s than a full–grown one’s. Remember Konrad Lorenz’s “innate releasing mechanism”? In addition to that observation, a surfeit of other studies reveal that infant faces, especially smiling ones, create a “pleasure response” in adults.
If that’s true, then our more apelike ancestors may have begun to prefer mates who retained more youthful traits into their adulthood—higher foreheads, larger skulls and eyes, flatter faces, and stronger chins. Females that grew up by genetic happenstance looking more childlike would have found themselves with more enthusiastic suitors than other women who looked less childlike. That increased the chances that those baby–faced traits would be passed along to both female and male children, leading to still more neotenic looks in all of us.
But in addition to triggering caretaking and pleasure responses, youth is, as we know, also a fitness indicator. It goes hand in hand with health, strength, and fertility, giving members of the opposite sex still more reasons to prefer mates who retained their youthful looks beyond childhood. The process may have been long and slow, but over tens of millions of generations the simian appearance that had once defined our human ancestors morphed from sloped brows, protruding snouts, and receded chins into more childlike traits. We can see exactly this transformation in the faces of our ancestors, species by species, as we march from the deep past toward the present. By the time
Homo sapiens
had emerged two hundred thousand years ago, our youthful looks had pretty much reached their current state.
A Preference for Youth Is Still Shaping Our Evolution
If more proof is needed of our preference for youth in potential mates, a study performed by scientists in Scotland, Japan, and South Africa seems to have supplied it. You may not find it terribly surprising that the research uncovered that men prefer women whose faces look more feminine, which is to say youthful; but it also turns out that that women preferred
men
whose faces looked more feminine, or boyish.
For the study, scientists digitally created an average, but attractive version of two faces for each sex, one Caucasian and one Asian, four “average” faces in all. They then digitally modified each face to create two versions, one slightly more masculine, the other slightly more feminine and childlike. The changes are subtle, but the male versions of the faces sport slightly heavier eyebrows, a hint of shaved beard, squarer jaws, and pupils that stand a bit farther apart than female pupils, something that tricks the eye into thinking that the male faces in the study were larger than their feminine counterpart (they weren’t).
When forced to rate the faces they found most attractive, members of both sexes, old and young, Asian and Caucasian, said they preferred the more feminine versions. In addition, when prompted to rate the faces on something more than attractiveness, such as trustworthiness, warmth, cooperativeness, and the likelihood to be a good parent, again the more feminine faces were preferred, although youthful looks didn’t seem to make the study’s participants feel that feminine faces were either more or less intelligent.
If we have such a universal preference for feminine, youthful looks, then why don’t men and women today, after millions of years of evolution, look essentially identical? Because some other factors are involved. A man’s bigger body, larger muscles, and broader shoulders can also indicate a good protector and provider. Those traits require more testosterone, and more testosterone causes changes in a man’s face you don’t see in a woman’s; a beard, thicker eyebrows, broader jaws, and a bigger head, for example. So, while male and female
Homo sapiens
look more
like one another than any other humans, and certainly more than full–grown great apes, we don’t look identical. But in time we might because, clearly, even today, we remain genetically predisposed to find younger, more childlike faces attractive.
The slow realignment of our looks over millions of years may have caused us to appear more childlike, but as we evolved and became more self–aware, apparently even this failed to make us attractive enough, because for at least the past fifty thousand years we have creatively and enthusiastically taken matters into our own hands, modifying our looks without waiting for genes and evolution to get around to the job. You and I can’t take much credit for the blue eyes or blond hair, long, thin bodies or the round, stout ones, that our parents passed along to us for the simple reason they are nothing more than a genetic toss of the dice. But the extravagant measures we take to enhance our appearance that Darwin studied so exhaustively illustrate, pretty dramatically sometimes, something that we do that other animals don’t, even other primates. We imaginatively elaborate our appearance, which may be one of the key behaviors that separate us from the rest of the animal world. But what is even more intriguing is that we don’t simply tinker with our looks; we change our behaviors, too. We don’t simply try to
look
sexy, we try to
act
sexy, and that, as a species, has taken us into entirely new territory.
Some of these modifications have obvious animal analogues, but with distinctly human twists. For example, why roar like a lion when you can show up on a date with a Porsche Carrera, or Harley–Davidson Night Rod Special. We not only use clothing to protect us from the elements, but also to improve our looks and make statements about status, power, and confidence. These behavioral elaborations even help to explain our affection for what sociologist and economist Thorstein Veblen termed “conspicuous consumption” in his landmark 1899 book
The Theory of the Leisure Class
. Possessions—the latest smartphone, the most fashionable house, the biggest diamond, the hottest dress, the richest fabrics—are all human made fitness indicators.
You might say, well, this all seems fairly banal, finding ways to make yourself more attractive to the opposite sex, and I am willing to agree. But you can make a powerful argument that efforts to enhance
and amplify ourselves to impress potential sexual partners laid the foundation for far more creative endeavors, undertakings that have made much of modern human culture possible—song, art, invention, wit, storytelling, and humor. It could be argued that the foundations of human creativity and culture can trace their roots to our early efforts to consciously make ourselves more irresistable.
Psychologist Geoffrey Miller has argued that just as shapely bodies and symmetrical, youthful faces signal physical fitness, creativity itself is a sign of a mental fitness, something that has enormous value to a potential mate, and therefore a trait that evolution would “encourage.”
Of course the organ that is the engine of all of this creativity is your brain. It may have evolved to make sense of the world you live in, but among us
Homo sapiens
it has become extraordinarily effective in generating all sorts of appealing behaviors and countless personal decisions that make you cooler, sexier, and downright captivating. It enables you to be witty, conjure startling ideas, master the piano, helps you dance better or sing beautifully, or become a more stable and loyal partner. It’s a kind of universal machine that can turn itself to nearly any goal, including the sexual capitulation of the opposite sex. Once our brains found themselves self–aware, Miller argues, it emerged as nature’s ultimate indicator of fitness. Just as genes can deliver vibrant feathers or neon colors, brains bent themselves to the work of upping our desirability in a million different ways. He calls this the “healthy brain theory.”
The idea that creative behavior makes us sexier isn’t brand–new. The old master Darwin, keeping in mind the antics of prancing and warbling birds, speculated in
The Descent of Man
that humans used both dance and song to win the hearts of potential mates. “I conclude that musical notes and rhythm were first acquired by the male and female progenitors of mankind for the sake of charming the opposite sex. Thus musical tones became associated with some of the strongest passions an animal is capable of feeling … We can thus understand how it is that music, dancing, song and poetry are very ancient arts.”
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In another part of the book he writes, “As neither the enjoyment nor the capacity of producing musical notes are faculties of the least use to man in reference to his daily habits of life, they must be ranked among the most mysterious with which he is endowed … Whether or not the
half–human progenitors of man possessed … the capacity of producing, and therefore no doubt appreciating, musical notes, we know that man possessed these faculties at a very remote period.”
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