Do Gentlemen Really Prefer Blondes?: Bodies, Behavior, and Brains--The Science Behind Sex, Love, and Attraction

Many years ago the behavioral psychologist Arthur Aron put opposite-sex college students in a room and asked them to reveal intimate details of their lives: their most embarrassing moments, what they'd do if their parents died, and so on. Then he paired them up, man and woman, and told them to lock eyeballs for four minutes. No talking, no smiling—just gazing. Deep gazing, like lovers. Later, Aron quizzed the students on how they felt about their partners. Deeply attracted, most said. So deeply that a couple that were strangers on the day of the experiment allegedly got married six months later. You might open the heart by sharing intimacies, but, evidently, you reach it through the eyes.

Looking directly into a lover's eyes is like looking into fire. As Nietzsche put it, "If you gaze for long into an abyss, the abyss gazes also into you." Thanks to a shot of adrenaline, your palms sweat, your breathing gets shallow, your skin feels hot, and your pupils dilate. Your amygdala, the center of the brain that processes emotion, blazes with activity. At the same time you produce dopamine, a "_feel-good" neurotransmitter that is associated with passion and addiction, and oxytocin, a hormone related to bonding. So intense is the mutual gaze that there's only one way to amp it up: deeply penetrate your partner's eyes during slow rhythmic sex, as prescribed in the Kama Sutra (not recommended with a stranger).

The most fascinating theory about eye gaze is that just the act of doing it can enhance, or even initiate, a feeling of love. Most of the time we think that our faces reflect what's going on inside our heads, but, for at least some people, the expression on their face becomes a genuine feeling. Psychologists call this facial feedback, and Darwin was among its first believers.

The facial feedback hypothesis was borne out in experiments at Clark University and the University of Alaska. At Clark, more than seventy opposite-sex strangers, under the pretext of an ESP study, silently gazed into each other's eyes for two minutes. Participants who were previously assessed and known to respond emotionally to their own facial expressions reported a significant increase in passionate love for the strangers in whose eyes they had gazed. (The gaze must be mutual and nonthreatening.) At the University of Alaska, eye-gazers who scored high on a standard psychological test known as the Romantic Beliefs Scale had the same experience. Men and women who felt strongly about concepts such as a "one and only love," "love at first sight," and "love will find a way" felt a significant surge of romantic love after locking eyes.

According to the facial feedback hypothesis, you might feel tenderhearted toward people after gazing into their eyes because you're acting like a person in love. If anyone saw you softly gazing at someone, they'd think you were in love. You're conscious of the facial muscles that create the expression on your face that everyone sees, and you internalize it. Your neural reward circuits fire up, and you feel how you act. It's no wonder that professional actors whose characters are in love often fall in love with each other on the set. Of course, causal facial feedback works only if you're aware of and respond to your personal bodily cues. Not everyone does; you may need to be primed by a previous emotional connection or have strong romantic beliefs.

Assuming you are a romantic, gazing into another person's eyes makes that person appear more attractive to you, and just might help you fall in love. But is it real love? That remains to be seen.

Why do men prefer big pupils?

The film Kinsey, a biopic about the provocative _twentieth-_century sex researcher Alfred Kinsey, reenacts a moment from one of his famous lectures on the human body. Kinsey turns to a prudish young woman and asks, "What organ in the human body can expand its size a hundred times?" She blushes crimson. "I'm certain I wouldn't know," she replies. Kinsey raises his eyebrows. "I'm talking about the iris of your eye," he says chidingly, and remarks that the young lady could be disappointed if she persists in her way of thinking.

It turns out the iris and the pupil are erotic in their own right. The iris is the colored part of the eye surrounding the pupil, and the pupil is the black "bull's-eye" of the eyeball. The muscles of the iris expand and contract the pupil from less than 1 mm to nearly 10 millimeters in diameter. The pupil is arguably the face's most blatant and bewitching feature. A wide-open pupil intensifies a person's gaze. Those big black holes suck you in, like it or not.

Everyone knows that pupils dilate in the dark, but there's more to it than meets the eye. In the 1960s, the psychologist Eckhard Hess discovered that pupils also dilate when people are aroused or emotionally charged. Women's pupils dilated when they saw images of children or male nudes, and men's pupils dilated when they saw female nudes. It's an involuntary reflex of the sympathetic nervous system.

Pupil size is also detected unconsciously. When Hess asked men to judge two pictures of a woman that were identical in every way but the woman's pupil size, the guys overwhelmingly preferred the version with larger pupils. Forced to explain why they thought the woman was more attractive in that picture, the men shrugged and said she just seemed prettier and more feminine. No one consciously noticed the difference in her pupils.

Evolutionarily speaking, men prefer big, gaping pupils because they're a sign of arousal and receptivity. If your pupils are dilated when you're talking to a guy (and you're not drunk or drugged), it's a sign that you're attracted to him. Your pupils dilate widest around ovulation, the fertile phase of the menstrual cycle, and when you're fairly young. As you grow older, your pupils can't dilate as much as they did in childhood and young adulthood. Big pupils are cues of youth, fertility, and receptivity—in the subconscious male mind, a sight to behold.

Women, meanwhile, are less enthusiastic about men with big pupils. A study at York University in Canada found that gals prefer guys with medium-sized pupils. While men regard pupil dilation as a promising sign of arousal, women are often suspicious of it. A wound-up, wild-eyed guy might force you to have sex, or he might be madly overpossessive or somehow out of control. (The few women who preferred men with big pupils tended to also prefer "bad boys.") If a man's pupils are too big, a woman's might contract.

What makes a face good-looking?

While you're walking down the street, you pass a person so drop-dead gorgeous that everyone—male, female, straight, gay, tourist, octogenarian, and infant—turns his or her head and says, "Oh!" What is it about that face? What magic do the beautiful have that most of us lack? Even poets struggle to find the words. Emily Dickinson simply said, "Beauty is not caused. It is."

Where poets rhapsodize, scientists analyze—neuroscientists, psychologists, and anthropologists have all taken a stab at deconstructing facial beauty. Overall, they've focused on three measures: averageness (how closely the size and shape of facial features match the average), symmetry (how closely the two sides of the face match), and sexual dimorphism (how feminine or masculine the face appears). We're only talking about facial shape and features here, not age, expression, or complexion.

You might think the first one, averageness, seems odd. By definition, isn't average just average? But most of us don't have average features. When compared to the average, your eyes may be too wide or close-set, your eyebrows uneven, or your nose too sharp. When a batch of faces is "averaged" to make a computer-generated composite, judges rate the composite as more attractive than any one of the faces that constitute it. The more faces blended in the composite, the more attractive the result.

Blending races helps, too. Psychologist Gillian Rhodes asked Asians (Japanese) and Caucasians to rate the attractiveness of male and female faces. Subjects from both cultures thought mixed-race Eurasian composites were much more attractive and healthier-looking than composites of all-white or all-Asian faces. Double-checking her results, Rhodes did another study using the faces of actual Eurasian people, not composites, and reached the same conclusion. The biracial faces were judged better-looking. Maybe that's why so many models come from Brazil, where so many people are biracial or multiracial.

So what draws us all to the middle? Researchers have several theories. For one, familiarity breeds attraction—we learn to identify patterns in the faces we see, and calibrate our perceptions to match these known patterns. Averaging all the faces we've seen, medium proportions would be more familiar to most of us than distinctive features such as potato noses, wide-set eyes, underbites, and chipmunk cheeks. (However, if you grew up around people with distinctive features, you'd probably find them more attractive than someone who did not.) Distinctive and unattractive features may be telltale signs of undesirable recessive genes. Looking at portraits of the inbred Habsburgs, you can see how members of the ruling house of Europe shared the same DNA to the extent that their looks and health suffered—it shows up in their protruding lower lips, misshapen noses, and doorknocker mandibles. Poor Charles II had a jaw so deformed that he could not chew.

Even an infant might turn her nose up at the Habsburgs, according to studies that suggest that "beauty detectors" are hardwired in our brains. Remarkably, babies who have had very little previous exposure to people have the same facial preferences as adults. Infants as young as one day old, when exposed simultaneously to beautiful and unattractive faces, consistently gaze longer at the attractive faces. The neural mechanism that enables babies to distinguish beautiful from beautiless is unknown, but it is widely agreed that it exists. People from different cultures also generally agree on what faces are hot or not.

Beauty isn't created equal, as you might expect. There's beauty and there's bedazzling beauty. The most striking faces are close to the average but with certain optimal "tweaks." Evolutionary psychologist David Perrett demonstrated this by taking a composite of an attractive female face and selectively modifying her features, gifting her with higher cheekbones, larger eyes, and shorter distances between her mouth and chin and nose and mouth. This tweaked composite won the beauty contest over the attractive averaged composite in the way that supermodels trump catalog models. It turns out that atypical features can enhance a person's looks—but only in the right place on the right face.

Symmetry, the second measure of beauty, can make or break the equation. Look at actress Gwyneth Paltrow for an example of a beautiful but slightly atypical face. Her mouth is wider than average, and so is the space between her eyes. On another person these distinctive features might not be so stunning, but Gwyneth's face happens to be perfectly symmetrical. This is also true of hotties such as Denzel Washington, Kate Moss, Christy Turlington, and Cindy Crawford (minus the mole).

Not all beautiful faces are symmetrical and not all symmetrical faces are beautiful, but symmetry often plays a role in attraction. Like averageness, symmetry suggests developmental stability. If you grow up with symmetrical features—despite risk of disease, genetic mutations, starvation, pollution, and parasites—there's a better chance you're fit and healthy and your body can ward off infection. Researchers at the University of New Mexico measured the chin length, jaws, lip width, eye width, and height of more than four hundred men and women to determine their facial symmetry. Comparing the results against each participant's health records, they found that people with the most symmetrical features were healthier (i.e., had shorter and fewer respiratory infections and took fewer antibiotics).

Masculinity or femininity (sexual dimorphism) is the third measure of attractiveness. In men, the hormone testosterone is behind prominent jawlines and cheekbones, thicker brow ridges, larger noses, smaller eyes, thinner lips, facial hair, and a relatively long lower half of the face. Women are attracted to rugged, masculine faces because they signal strong immune systems and, potentially, high fertility and social status. Strikingly, women's levels of the hormone estrogen influence how attracted they are to masculine faces. The higher a woman's estrogen level, the more she is attracted to cues of masculinity (see page 124). Estrogen is also behind the beauty of female faces. It plumps out women's lips and skin and produces smaller and pointier chins, smaller noses, rounder cheekbones, eyebrows high above the eyes, and a bottom of the face that is narrower than the top half.

Anthropologist Donald Symons, who in the 1970s first proposed that average faces are beautiful faces, said that we all have "beauty detection" devices in our heads, and it appears he was right. We calculate averageness, symmetry, and sexual dimorphism as easily as Newton calculated numbers. But remember: These three rules only represent physical attractiveness in a general way. Researchers haven't been able to measure the beauty in a person's eyes or the exquisiteness of an expression. For that greater truth you still need poetry.

Beauty is truth, truth beauty.
—Keats

How long does it take to decide if a person is hot?

To find out exactly how quickly we can tell if a person is hot or not, neuroscientists Ingrid Olson and Christy Marshuetz devised a sneaky experiment. They exposed men and women to a series of pre-rated faces, some gorgeous and others homely, and asked them to rate their appearance. The twist was that the faces flickered on the screen for only thirteen milliseconds—a flash so fast that the exasperated viewers swore they didn't see anything. Yet when forced to rate the faces they thought they didn't see, the judges were uncannily accurate. Without knowing why, they gave good-looking faces significantly higher scores than unattractive ones.

The fascinating implication here is that beauty is perceived subconsciously. It's not as if the subjects had much time to meditate on anyone's hotness—they weren't even aware of seeing a face. To a great extent, first impressions of people's looks are less about choice and culture and cultivated tastes, and more about something deeper and universal. Judging attractiveness seems to happen just as automatically and matter-of-factly as judging identity, gender, age, and expression.

When you see an attractive face, reward centers of your brain known as the nucleus accumbens and orbitofrontal cortex are stimulated, as well as the amygdala, which captures expression. You also have a specialized cortical network known as the fusiform facial area, which, in a glance, may process a person's whole face: its contour, configuration, and features such as eyes, nose, and lips. It takes coordination between these areas of the brain and others, including the temporal and occipital lobes of the right hemisphere, to form a complete impression of a person's appearance. While some parts of your brain can capture a face in thirteen milliseconds, up to two hundred milliseconds may actually tick by before other parts process the face and a perception emerges on the screen of your consciousness.

Even so, you're faster than you think.