What distinguishes blonde hair from all other hair colors is that it changes dramatically with age. Young girls with light blonde hair usually grow up to be women with brown hair (although there are a very few women who retain their light blonde hair into adulthood). Thus, if men prefer to mate with women with blonde hair, they are unconsciously attempting to mate with younger (and hence, on average, healthier and more fecund) women with greater reproductive value and fertility. It is no coincidence that blonde hair evolved in Scandinavia and northern Europe, where it is very cold in winter. In Africa, where our ancestors evolved for most of their evolutionary history, people (men and women) mostly stayed naked. In such an environment, men could accurately assess a woman’s age by the distribution of fat on her body or by the firmness of her breasts (as discussed above). Men in cold climates did not have this option, because women (and men) bundled up in such environments. This is probably why blonde hair evolved in cold climates as an alternative means for women to advertise their youth.22 Men then evolved a predisposition to prefer to mate with women with blonde hair in response, because those who did on average had greater reproductive success than those who did not, because, unbeknownst to them, they ended up mating with younger, healthier women with greater reproductive value and fertility.
Incidentally, this also suggests that the stereo type that blondes are dumb may have some statistical basis. Why do people believe that blondes are dumb? Recall that the human brain, including the stereo types that it generates, is adapted to the ancestral environment. What would be the average age of light blondes in the ancestral environment (say, northern Europe ten thousand years ago) in the absence of hair dye? Roughly 15. What would be the average age of brunettes in the same environment? Roughly 35. A 15-year-old woman is bound to be more naïve and less experienced, mature, and wise (in other words, “dumb”) than a 35-year-old woman, no matter what her hair color. It’s not that blonde women are dumber than brunette women; it’s that younger women are “dumber” (less knowledgeable) than older women, and blonde hair is a reliable indicator of extreme youth. The same logic is probably behind the stereo type that women with large breasts are dumb. In the ancestral environment, without plastic surgery or even bras, only very young women had large, firm breasts.
Blue Eyes
The typical description of ideal beauty always goes “blonde, blue eyes.” After Marlowe proposed a solution for the mystery of why men prefer women with large breasts, the attraction to blue eyes remained the only mystery to solve in the area of traits associated with physical attractiveness. We now knew why men preferred women with all the traits that characterize Barbie or a typical blonde bombshell, and we knew the evolutionary logic behind each of them. But eye color, more so than hair color, seems such an arbitrary trait. Why should women with blue eyes be any different from those with green or brown eyes? Yet a preference for blue eyes seems both universal and undeniable.23
There is an additional layer to the mystery of blue eyes. Unlike all the other traits discussed above, which are considered to be attractive only for women, blue eyes are thought to be attractive for both women and men. For instance, a typical description of an attractive man is “tall, dark, and handsome,” not blond; unlike blonde women, blond men are not universally considered to be attractive (because women generally prefer to mate with older, not younger, men).24 Yet, as the examples of Frank Sinatra (“Ol’ Blue Eyes”) and Paul Newman show, men with blue eyes are considered to be attractive, just like women with blue eyes. So it appears that the answer to the question, “Why are blue eyes attractive?” must involve more than male sexual preference.
The attraction of blue eyes remained an evolutionary mystery until an undergraduate student, Lee Anne Turney, suggested a novel solution in her term paper for a class that she took from one of us (Kanazawa) in spring 2002. As far as we know, hers is the only available explanation for the attraction of blue eyes that anyone has ever proposed, and it has at least surface plausibility. But, of course, it will have to be subjected to rigorous experimental testing before it can become an accepted explanation.
Turney points out that the human pupil dilates when an individual is exposed to something that he or she likes.25 For instance, the pupils of women and infants (but not men) spontaneously dilate when they see babies. Thus, pupil dilation, which is usually beyond an individual’s conscious volitional control, can be used as an honest indicator of interest and attraction. Most people are not even aware that the size of their pupils changes when they see something they like, so it would be difficult to deceive others by consciously manipulating their pupil size. We cannot help but reveal our interest in and attraction to others through the size of our pupils.
Turney then makes two simple observations. First, every human pupil is dark brown, regardless of the color of the iris, which encloses the pupil and determines the color of the eye. Second, blue is the lightest color of human iris. The consequence of these two observations is that the size of the pupil is easiest to determine in blue eyes. If you face people with different eye colors and must determine whether each person likes or is interested in you, with all else equal, it is easiest to read the blue-eyed person’s level of interest or attraction. Turney’s argument, which we believe might be true, is that blue-eyed people are considered attractive as potential mates because it is easiest to determine whether they are interested in us or not. It is easier to “read the minds” of people with blue eyes than of those with eyes of any other color, at least when it comes to interest or attraction.
One of the advantages of Turney’s solution is that it not only explains why blue eyes are considered to be ideal in mates but also explains why, unlike all the other traits we discuss in this section, blue eyes are considered to be attractive in both sexes. It is just as important for women to read men’s minds as it is for men to read women’s; if anything, given the far greater consequences of making mistakes by being attracted to the “wrong” person, women should have a greater need to decide whether their potential mate’s seeming interest in them is genuine or not. The negative consequences of being fooled by a lying suitor are much greater for women, so blue eyes should be a more important characteristic in men than in women.
Incidentally, we believe that Turney’s logic can also explain why people with dark brown eyes are often considered to be “mysterious.” They are mysterious because their minds—that is, whether or not they are interested in or attracted to us—are more difficult to assess. The color of the dark brown iris is very similar to the (universal) color of the pupil, and so it is very difficult to gauge the size of the pupil in dark brown eyes. Many people, both men and women, express dislike for extremely dark brown eyes.26
The Big Irony: Why Modern Men Are Fooled
So men like women who look like blonde bombshells, or Barbie, and women want to look like them, because each of their key features (youth, long hair, small waist, large breasts, blonde hair, and blue eyes) is an indicator of youth and thus of health, reproductive value, and fertility. There is precise evolutionary logic behind the image of ideal female beauty. By now, astute readers may have caught on to the irony of it all. None of what we have said above is true any longer. Through face-lifts, wigs, liposuction, surgical breast augmentation, hair dye, and color contact lenses, any woman—regardless of age—can have many of the key features that define the ideal female beauty. Very little of Pamela Anderson’s appearance is natural. A 40-year-old woman today can rely on modern technology to continue to look like a 20-year-old woman. Farrah Fawcett at 60 looks better than most “normal” women half her age.
And men fall for them. As the Savanna Principle suggests, their brains cannot really comprehend silicone breasts or blonde hair dye, because these things did not exist in the ancestral environment ten thousand years ago. Men can cognitively understand that many blonde women with firm large breasts are not actually 15 years old, but they still find them attractive because their evolved psychological mechanisms are fooled by the
modern inventions that did not exist in the ancestral environment.
Q. Why Is Beauty Not in the Eye of the Beholder or Skin-Deep?
They say beauty is in the eye of the beholder, which means that different people possess different standards of beauty and that not everyone agrees on who is beautiful and who is not. They also say beauty is skin-deep, which means that there are no real differences between attractive and unattractive people besides their looks. Both of these sayings make perfect sense from the perspective of the Standard Social Science Model. Since humans are born with blank slates for minds, the logic goes, everything, including tastes for and standards of beauty, must be acquired after birth through socialization. As different people have different life experiences in different cultures, they naturally acquire different standards of beauty. Some features are considered to be beautiful by some people in some cultures, and completely different features are considered beautiful by other people in other cultures. The differences between attractive and unattractive people are therefore arbitrary.
On the surface, both the sayings “beauty is in the eye of the beholder” and “beauty is only skin-deep” and the Standard Social Science Model explanations for them appear plausible. Many introductory sociology and anthropology textbooks, for example, include pictures of people who are considered to be beautiful in different cultures, and some of them look quite bizarre to the contemporary Western eye. However, evolutionary psychological research has once again overturned this common assumption and widespread belief.
As it turns out, the standards of beauty are universal, both across individuals in a single culture and across all cultures.27 Within the United States, both East Asian and white individuals28 and white and black individuals29 agree on which faces are more or less attractive. Cross-culturally, there is considerable agreement in the judgment of beauty among East Asians, Hispanics, and Americans;30 Brazilians, Americans, Russians, the Aché of Paraguay, and the Hiwi of Venezuela;31 Cruzans and Americans in Saint Croix;32 white South Africans and Americans;33 and the Chinese, Indians, and the English.34 In none of these studies does the degree of exposure to the Western media have any influence on people’s perception of beauty. If, as the Standard Social Science Model contends, the standards of beauty are acquired and learned through socialization within different families and cultures, how is it possible for people from such diverse cultures to agree broadly on who is beautiful and who is not?
It appears that people from different cultures share the same standards of beauty because they are innate. Two studies conducted in the mid-1980s in dependently demonstrate that infants as young as two and three months old gaze longer at a face that adults judge to be more attractive than at a face that adults judge to be unattractive, indicating the infants’ preference for attractive faces.35 In the most recent version of this experiment, newborn babies less than one week old show significantly greater preference for faces that adults judge to be attractive.36 Another study shows that 12-month-old infants exhibit more observable plea sure, more play involvement, less distress, and less withdrawal when interacting with strangers wearing attractive masks than when interacting with strangers wearing unattractive masks.37 They also play significantly longer with facially attractive dolls than with facially unattractive dolls. The findings of these studies are consistent with the personal experiences and observations of many parents of small children, who find that their children are much better behaved when their babysitters are physically attractive than when they are not.
Because even the most ardent proponents of the Standard Social Science Model would admit that one week (or even a few months) is not nearly enough time for infants to have learned and internalized the cultural standards of beauty through socialization and media exposure, these studies strongly suggest that the broad standards of beauty might be innate, not learned or acquired through socialization. The balance of evidence seems to indicate that beauty is decidedly not in the eye of the beholder, but might instead be part of universal human nature. In other words, “beauty is in the adaptations of the beholder.”38
But this simply begs the question: Why are the standards of beauty innate? Why are we born with a common general perception as to who is beautiful and who is not? What is the evolutionary logic behind this?
There appear to be a few features that characterize physically attractive faces: bilateral symmetry, averageness, and secondary sexual characteristics.39 Attractive faces are more symmetrical than unattractive faces.40 Bilateral symmetry (the extent to which the facial features on the left and the right sides are identical) decreases with exposure to parasites, pathogens, and toxins during development,41 and with genetic disruptions such as mutations and inbreeding.42 Developmentally and genetically healthy individuals have greater symmetry in their facial and bodily features, and are thus more attractive. For this reason, across societies, there is a positive correlation between parasite and pathogen prevalence in the environment and the importance placed on physical attractiveness in mate selection; people place more importance on physical attractiveness when there are more pathogens and parasites in their local environment.43 This is because in societies where there are a lot of pathogens and parasites in the environment, it is especially important to avoid individuals who have been afflicted with them when selecting mates.
Facial averageness is another feature that increases physical attractiveness; faces with features closer to the population average are more attractive than those with extreme features.44 In the memorable words of Judith H. Langlois, who originally discovered that the standards of beauty might be innate, “attractive faces are only average.”45 Evolutionary psychological reasons for why average faces in the population are more attractive than extreme faces are not as clear as the reasons for why facial symmetry is attractive. Current speculation is that facial averageness results from the heterogeneity rather than the homogeneity of genes. Individuals who have two different copies (or alleles) of a gene are more resistant to a larger number of parasites, less likely to have two copies of deleterious genes, and at the same time more likely to have statistically more average faces with less extreme features.46 If this speculation is correct, it means that, just like bilateral symmetry, facial averageness is an indicator of genetic health and parasite resistance.
Far from being merely in the eye of the beholder or skin-deep, beauty appears to be an indicator of genetic and developmental health, and therefore of mate quality; beauty is a “health certification.”47 More attractive people are healthier,48 have greater physical fitness,49 live longer,50 and have fewer lower back pain problems51 (although some dispute this conclusion).52 Bilateral symmetry measures beauty so accurately that there is now a computer program that can calculate someone’s level of symmetry from a scanned photograph of a face (by measuring the sizes of and distances between various facial parts) and assign a single score for physical attractiveness, which correlates highly with scores assigned by human judges.53 A computer program can also digitally average human faces.54 Beauty, therefore, appears to be an objective and quantitative attribute of individuals, like height and weight—both of which were also more or less “in the eye of the beholder” before the invention of the yardstick and the scale.
Q. Why Is Prostitution the World’s Oldest Profession, and Why Is Pornography a Billion-Dollar Industry?
It has often been remarked that female prostitutes cater to men, while male prostitutes also cater to men. Gay or straight, virtually all clients of prostitution are men, and very few women contract the ser vice of prostitutes. Why the sex difference? And why is prostitution the “world’s oldest profession”?
Because of the asymmetry in reproductive biology, men’s reproductive success is primarily constrained by the number of women to whom they have sexual access, whereas women’s reproductive success does not increase linearly with the number of men to whom they have sexual access.55 For example, if a man has sex with one thousand women in a year, he can potentially produce one thousan
d children, and realistically about thirty in a year. (The probability of conception per intercourse is about 0.03.) 56 In sharp contrast, if a woman has sex with one thousand men in a year, she can have only one child (barring a multiple birth) in the same time period, which she can achieve by having regular sex with only one man. The probability of a conception if a woman has sex with one man one hundred times (twice a week for a year) is 0.95.57 So, unlike for men, there is very little reproductive benefit for women in seeking a large number of sex partners.
For this reason, men are selected to desire a far larger number of sex partners than women do.58 On average, young men profess to desire about eight different sex partners in two years, whereas young women profess to desire only about one in the same time period. This is why men desire sexual variety (sexual intercourse with a large number of partners) to a far greater extent than women do.
Prostitution, the world’s oldest profession, is simply a consequence of men’s evolved desire for sexual variety. It could not have survived millennia as an industry if men did not have such a desire, and women’s lack of the same desire—at least to the same extent—explains why prostitution catering to women has not emerged.
Another indicator of sex differences in the desire for sexual variety is in sexual fantasies, which are expressions of both male and female sexual desires entirely unconstrained by reality.59 Thirty-two percent of young men surveyed in one study report that they have fantasized about sexual encounters with more than one thousand partners in their lifetime, whereas only 8 percent of women report the same variety of partners in their sexual fantasies. Further, men are far more likely than women to switch one imagined partner for another during a single sexual fantasy, thus allowing them to have (albeit imagined) sexual access to multiple partners. As for women’s fantasies, given their relatively greater tendency to desire sex in committed relationships rather than in anonymous encounters,60 women tend to prefer romance novels, not pornography, as their means of fulfilling sexual fantasy.61
Why Beautiful People Have More Daughters: From Dating, Shopping, and Praying to Going to War and Becoming a Billionaire–Two Evolutionary Psychologists Explain Why We Do What We Do Page 7