Woman

by Natalie Angier

  Conversely, androgens such as testosterone can inhibit breast adiposity. As we saw earlier, women who are genetically insensitive to androgen may grow very large breasts. Men whose gonads fail to produce enough testosterone sometimes suffer from gynecomastia. Without testosterone to keep breast growth in check, the men's small amount of estrogen has the opportunity to lay down selective depots of fat hurriedly, demonstrating once again that the line between maleness and femaleness is thin—as thin as the fetus's bipotential genital ridge, as thin as the milk ridge in all of us. Yet androgens don't entirely explain discrepancies in breast size among women either. Many women with comparatively high testosterone levels, women whose visible mustaches and abundant armpit hair make it clear that they are not insensitive to the androgens coursing through them, nonetheless have full frontal shelves. Thyroid hormones, stress hormones, insulin, growth hormone—all leave their smudgy fingerprints on mammogenesis. In sum, we don't know what makes the aesthetic breast. We don't have the hormonal recipe for the universal Mae West breast. If science fiction television is any indication, though, in the future, the heartbreak of "micromastia" (plastic-surgeon-speak for small breasts) will be surmounted, and if our brains don't get bigger, our breasts surely will. Today, the average nonlactating breast weighs two thirds of a pound and measures about four inches across and two and a half inches from chest wall to nipple tip. The average brassiere size is a 36B, and it has been since the modern bra was invented about ninety years ago. On television shows like Star Trek, however, every woman of every race, whether human, Vulcan, Klingon, or Borg, is as bold in bust as in spirit, and no cup less than C will be cast.

  Estrogen also helps spur the elaboration of the practical breast, the glandular tissue that presumably will soon secrete its clouded, honied sweat. A series of firm, rubbery ducts and lobes begin threading their way through the fat and ligamentous glue. Each breast usually ends up with between five and nine lobes, where the milk is generated, and each lobe has its independent duct, the conduit that carries the milk to the nipple. The lobes are subdivided into about two dozen lobules, which look like tiny clusters of grapes. The lobes and lobules are distributed fairly evenly throughout the breast, but all the ducts lead to a single destination, the nipple. As the ducts converge on the nipple, curling and bending like snakes or strands of ivy, their diameters widen. The circuitry of lactation follows the hydrodynamic pattern that we recognize from trees, or the veins in a leaf, or the blood vessels in the body. The lobes and lobules are the foliage, the fruits and leaves, while the ducts are the branches, thickening into a braid of trunks. But while in a tree or the body's vasculature the fluid of life is pumped from the widest conduit out to the narrowest vessel or vein, here the milk is generated in each tiny lobular fruit and pulsed to the spacious pipeline below. The ducts perforate the skin of the nipple, and though these portals ordinarily are concealed by the warty folds of the nipple tip, when a woman is nursing her nipple balloons out and looks like a watering can, each ductal hole visible and visibly secreting milk.

  The ducts and lobules do not fully mature until pregnancy, when they proliferate, thicken, and differentiate. Granular plugs the consistency of ear wax, which normally keep the ducts sealed up, begin breaking down. The lobules sprout microlobules, the alveoli. The dairy farmers commandeer the breast. They push fat out of the way to make more room for themselves. The breast gains as much as a pound while lactating. The areola, that pigmented bull's-eye surrounding the nipple, also changes markedly in pregnancy. It darkens and seems to creep down the hillock of the breast, like lava spreading slowly from the peak of a volcano. The areola is permeated by another set of modified sweat glands, the little goosebumps called Montgomery's glands, and the bumps multiply in the maternal breast and exude lubricating moisture to make the sensation of suckling bearable. After weaning, the lobules atrophy, the ducts regress, the areola retreats, and the fat reclaims dominion over the breast—more or less. Women who breastfeed their children often complain that their breasts never recover their former bounce and bulk. The fat grows lazy and fails to reinfiltrate the spaces from which it was edged out by the gland. The aesthetic breast is a bon vivant, after all, a party favor. For reliability, look to the ducts and lobules. They'll return when needed, and they're not afraid to work up a sweat.

  Breasts weigh a few ounces in fact and a few tons in metaphor. As Marilyn Yalom describes admirably in her cultural study A History of the Breast, the breast is a communal kiosk, open to all pronouncements and cranks, and the endorsements of the past are easily papered over with the homilies of today. The withered tits of witches and devils represented the wages of lust. In Minoan statues dating from 1600 B.C., priestesses are shown with bare, commanding breasts and snakes wrapped around each arm. The snakes strain their heads toward the viewer, their extended tongues echoing the erect nipples of the figurine, as though to warn that the powerful bosom they bracket might as soon dispense poison as love. The breast is a bralette, able to accommodate more or less. The multibreasted goddess seen in many cultures projects tremendous strength. So too do the Amazons, those mythical female warriors who lived apart from men, consorting with them once a year solely for the sake of being impregnated, and who reared their daughters but slayed, crippled, or abandoned their sons. The Amazons are most famed for their self-inflicted mastectomies, their willingness to cut off one breast to improve their archery skills and thus to resist conquest by the male hordes surrounding them. For men, Yalom writes, "Amazons are seen as monsters, viragos, unnatural women who have misappropriated the masculine warrior role. The missing breast creates a terrifying asymmetry: one breast is retained to nurture female offspring, the other is removed so as to facilitate violence against men." For women, the Amazon represents an inchoate wish, a nostalgic longing for the future. "The removal of the breast and the acquisition of 'masculine' traits suggests this mythic Amazon's desire to be bisexual, both a nurturing female and an aggressive male, with the nurturance directed exclusively toward other women and the aggression directed exclusively toward men." A softened variant of the Amazon icon occurred in eighteenth-century France, when the figure of Liberty often was shown with one breast clothed, the other bared, her willingness to reveal her breast (or at least her indifference to her temporary state of dishabille) evidence of her commitment to the cause. More recently, women who have had a breast surgically removed for the treatment of cancer have assumed the mantle of the Amazon warrior and proudly, angrily publicized their naked, asymmetrical torsos on magazine covers and in advertisements. Where the breast once was, now there is a diagonal scar, crossing the chest like a bow or a bandolier, alarming, thrilling, and beautiful in its fury.

  The breast has been used like a cowbrand, to denote possession. In Rembrandt's famous portrait The Jewish Bride, the husband, considerably the elder of the two, is shown with his right hand covering the bride's left breast, claiming her, including her within his gentle, paternal jurisdiction, and her hand reaches up to graze his groping one—though whether as an expression of modesty, concurrence, or hesitation is left gorgeously unclear. In nineteenth-century America, female slaves being put up for auction were photographed barechested, to underscore their status as beasts to be bought. In driving a metaphor home, breasts were beaten, tortured, and mutilated. In the seventeenth century, women accused of witchcraft often had their breasts hacked off before they were burned at the stake. When Anna Pappenheimer, a Bavarian woman who was the daughter of gravediggers and latrine cleaners, was condemned as a witch, her breasts were not merely cut off but stuffed into her mouth and then into the mouths of her two grown sons, a grotesque mockery of Pappenheimer's maternal role.

  Early scientists too had to have their say on the breast. In the eighteenth-century, Linnaeus, the ever-colorful Swedish taxonomist, paid the breast a dubious honor by naming an entire class after it: Mammalia, literally "of the breast," a term of Linnaeus's invention. As Londa Schiebinger has described, Linneaus could have chosen from other features that
mammals were known at the time to have in common. We could have been classified as Pilosa, the hairy ones, or as Aurecaviga, the hollow-eared ones (a reference to the distinctive three-boned structure of the mammalian middle ear), or as bearers of a four-chambered heart (term uncoined and perhaps uncoinable). But despite the derision of some of Linnaeus's contemporaries, we and our fuzzy, viviparous kin became mammals. It was the Enlightenment, and Linnaeus had a point to make, and so again the breast was called upon to service metaphor. Zoologists accepted that humans were a type of animal, as uncomfortable as the notion was and remains. A taxon was needed that would link humans to other species. Whatever feature Linnaeus chose to highlight as the bond between us and them inevitably would become the synecdoche of our beastliness. All mammals are hairy, but men are hairier than women, so Pilosa wouldn't do. The structure of the ear is too dull to merit immortalization through nomenclature. The breast, however, has romance and resonance, and best of all, it is most highly articulated in women. In the same volume in which Linnaeus introduced the term Mammalia, he also gave us our species name, Homo sapiens, man of wisdom, the category distinguishing humans from all other species. "Thus, within Linnaean terminology, a female characteristic (the lactating mamma) ties humans to brutes, while a traditionally male characteristic (reason) marks our separateness," Schiebinger writes. Thinkers of the Enlightenment advocated the equality and natural rights of all men, and some women of the time, including Mary Wollstonecraft and Abigail Adams, John's wife, argued that women too should be given their due rights—enfranchisement, for example, or the rights to own property and divorce a brutal spouse. The husbands of the Enlightenment smiled with tolerance and sympathy, but they were not prepared to peep over that political precipice. Through zoology and the taxonomic reinforcement of woman's earthiness, rational men found convenient justification for postponing matters of women's rights until woman's reason, her sapientia, was fully established. (Interestingly, though, human milk has often been characterized as the purest and most ethereal of body fluids, the least brutish aspect of a woman, as we will see in the chapter that follows.)

  In the nineteenth century, some scientists used the breast as phrenologists have used the skull, to demarcate and rank the various human races. Certain breasts were more equal than others. The European breast was drawn as a hemisphere standing at full attention—meet the smart and civilized breast. The breast of an African woman was portrayed as flabby and pendulous, like the udder of a goat. In abolitionist literature, illustrations of female slaves gave them high, round, sympathetic breasts—the melanized counterparts to the pop-up breasts of the slaves' tightly cinched mistresses.

  Linnaeus hog-tied us to other mammals by our possession of teats, but our breasts, we know, are ours alone. Evolutionary thinkers have known it too, and they have given us a wide selection of justifications for the human breast. As Caroline Pond says, there is little evidence to support any of the theories. We don't have a clue when in human evolution breasts first began their rise. Breasts don't fossilize. We don't know if they appeared before we lost our body hair or after, and in any event we don't know when—or why—we lost our body hair. But breasts are such a prominent feature of a woman's body that scientists keep staring at them, looking for clues. They are baffled by breasts, and they should be.

  Men don't have breasts, but they like to stake their claim on breasts, to grope their Jewish bride, and to feel they had a hand in inventing them. We must not be surprised if many evolutionary theories assume that breasts arose to talk to men. By far the most famous explanation in this genre comes from Desmond Morris, the British zoologist, who in 1967 wrote a spectacularly successful book, The Naked Ape, in which he presented a metaphor nonpareil, of breasts as buttock mimics. You've probably heard this theory in some form. It's hard to escape it. Like the Rolling Stones, it refuses to retire. As originally conceived, the theory rested on a sequence of assumptions, the first being that men and women needed to form a pair bond—better known as marriage—to raise children. The pair bond required the cultivation of sustained intimacy between partners, which meant intercourse was best done face to face rather than in the anonymous doggy-style position presumed to be the copulatory technique of our prehuman ancestors. To that end, the clitoris migrated forward, to give early women the incentive to seek frontal sex. For the gentlemen, the breast arose as an inspiration to modify their technique, offering a recapitulation ventrally of a body part they had so coveted from behind. In subsequent books, Morris has repeated the theory, illustrating it with photos comparing a good set of female buttocks with a good set of cleavaged knockers.

  Maybe he's right about breasts looking somewhat like buttocks, but who's to say that rounded buttocks didn't develop to imitate breasts, or that the two developed in tandem for their intrinsic aesthetic appeal? The high, rounded human buttocks are unlike the flat and narrow rump of many other primates. Morris and others argue that the gluteal hemisphericity surely came first, because the evolution of upright posture demanded greater musculature in the rump. The vertical configuration also created an area where energy could be stored as fat without interfering with basic movements, Timothy Taylor writes in The Prehistory of Sex. Moreover, upright posture introduced a need for alluringly shaped female buttocks, Taylor says. When a woman stands up, you can't see her vulva. The presentation of the vulva serves as an important sexual signal in many other primate species. If a woman isn't going to be flashing her vagina, she requires some other sexual signal rearguard, and the buttocks thus became accentuated. To ensure that she caught men's attention coming and going, the woman's breasts soon swelled too. Which is fine, except that women find a high, rounded butt on a man as alluring as a man does on a woman, and women notice it on women, and men on men. Beautiful buttocks are a thing to behold, but they need not have assumed their globular contours to provide a home for a large muscle. Instead, the curviness of the human rump on both sexes could well have been selected as another example of sensory exploitation, and of our preference for the curved and generous over the straight and narrow. The breast might not imitate the buttock so much as the two converge on a common theme.

  There are other reasons to be skeptical about the development of breasts as an encouragement to pursue frontal sex. Several other primates, including bonobos and orangutans, also copulate face to face, and the females wear no sexual badges on their chests, no clever replicas of their narrow rumps or swollen vulvas. Nevertheless, they are sought after—in the case of bonobos, many times a day. What is P. paniscus's secret, and does she have a catalogue?

  Because breasts, when not serving as visual lures, play an essential role in reproduction, many theorists have assumed that they developed to advertise to men some aspect of a woman's fecundity. Breasts certainly proclaim that a female is of reproductive age, but so do many other things—pubic hair, the widening of the pelvic bone, the wafting of hormonally activated body odors. A woman needs a certain percentage of body fat to sustain a pregnancy. Breasts are two parcels of fat. Perhaps they proclaim that a woman is nutritionally well stocked and so can bear and suckle children, a point that a prehistoric man, surveying the options among a number of calorically borderline women, conceivably would want to know. Yet breasts, for all their prominence, represent a small fraction of the body's total fat mass—4 percent, on average—and their size generally changes less in proportion to a woman's weight gain or loss than other fat depots of the body, like the adipose of the thighs, buttocks, and upper arms; thus breast fatness is not a great indicator of a woman's health or nutritional status. And as we saw above, breast size has nothing to do with a woman's reproductive or lactational capabilities and so is a poor signal of her maternal worth. Others suggest that breasts evolved to deceive, to confuse a man about a woman's current ovulatory status or whether she is pregnant or not, the better to mask issues of paternity and inhibit the tendency of men to kill infants they know are not their own. Why a man would be attracted to such devious commodities is unclear, unless
we assume that he is predisposed for another reason to love the look of a breast.

  Women have laid claim to breasts too. Meredith Small recasts the idea of breasts as mobile pantries, but sees them as designed to help women rather than to assure men that they are fertile. "A large breast might be simply a fat storage area for females who evolved under nutritional stress," she writes. "Ancestral humans walked long and far in their search for food, and they needed fat for years of lactation." Again, though, breasts are not the most liquid of fat assets, and they are surprisingly stingy about releasing their energy stores on demand. When a woman is lactating, lipid energy from the hips and thighs is far more readily mobilized than the fat of the breasts, even though the breast fat is much closer to the means of milk production. Helen Fisher proposes that breasts are a woman's pleasure chests, the swollen scaffolding beneath the erotogenic nipples ensuring that the breasts are caressed, sucked, and pressed against for maximum stimulation. Yet not all women have sensitive breasts, nor do they necessarily adore chronic fondling. "I've had a lot of experience in life," says a seventy-five-year-old woman in Breasts: Women Speak. "I've come to the conclusion that women get breast cancer because men handle their breasts too much. "At the same time, many men have very sensitive nipples, and they only wish women were more inclined to take a lick now and then.

  If not for the woman, then maybe for the child. Elaine Morgan, an original and brave thinker who continues almost single-handedly to push the aquatic ape theory of human evolution, has submitted several breast lines. She believes that humans spent part of their evolutionary development immersed in water, that we are part pinniped, part ape. One excuse for breasts, then, might be that they were Mae Wests, as the British soldiers of World War II called their life jackets—flotation devices that infants could cling to as they nursed. More recently, Morgan has suggested that hairlessness, another presumed legacy of our nautical phase, gave birth to the breast. Young monkeys and apes can cling to their mother's chest hair while they suckle, she says. Human infants have nothing to grab. In addition, they're so helpless, they can't lift their heads up to reach the nipple. The nipple has to come to them. Consequently, the nipple of the human breast is situated lower on the chest than the teat of a monkey is, and it is no longer anchored tightly to the ribs, as it is in monkeys. "The skin of the breast around the nipple becomes more loosely-fitting to make it more maneuverable, leaving space beneath the looser skin to be occupied by glandular tissue and fat," Morgan concludes. "Adult males find the resulting species-specific contours sexually stimulating, but the instigator and first beneficiary of the change was the baby." It's the empty-closet theory of the breast: if it's there, it will be stuffed. Apart from the lack of any evidence to support the aquatic ape theory, the putative benefits of the loosened nipple to nursing are not obvious. A woman must hold her baby to her breast, or prop the baby up with pillows, or strap the infant in place with a baby sling (which is how the vast majority of women in the developing world nurse their infants). If a mother were to spend much time hunched over a baby in her lap like Daisy the cow, her nipple dangling in the infant's mouth, she might find it difficult ever to straighten back to bipedalism again.