Sex, Time, and Power

by Leonard Shlain

  In most settings (more so in the past then the present), he understands that tofu is not a proper offering; neither is a solitary salad or a bowl of soup. An appetizer or dessert alone will rarely advance his suit. His “nuptial gift” most often must be red meat, and good red meat at that.

  Filet mignon is harvested from an animal’s psoas major muscle. Positioned alongside the vertebral column, deep in the most inaccessible interior region of the slaughtered animal’s abdomen, this muscle is a difficult one to retrieve. But more than its inaccessibility, its high preference value lies in its extremely low collagen content. Collagen is the substance that holds everything in the body together. It is tough stuff. Scar tissue, tendons, joint capsules, and adhesions consist mainly of collagen. The gristle in a steak is collagen. Its relative absence in filet mignon makes this the tenderest cut.

  The young woman sitting across from him, in her turn, appears to understand the terms of this transaction and will often order her filet medium rare. In the candlelight, one can discern iron’s presence glistening on the filet’s cut red surface. This is a very old deal.

  A young girl’s awakening to the power of her fertility marks a major milestone in her life.

  Chapter 11

  Menarche/Mustaches

  Sex is an antisocial force in evolution. Bonds are formed between individuals in spite of sex and not because of it.

  —E. O. Wilson1

  Put simply, in our evolutionary history, it seems likely that a woman’s value was usually her reproductive value, and a man’s value was his resource value.

  —Bobbi Low2

  Everywhere sex is understood to be something females have that males want.

  —Donald Symons3

  The differences and correlations between the puberty rites of boys and girls further forge the evolutionary link between sex and iron. Menarche, a girl’s first menses, typically begins around twelve years of age in industrialized societies. This life-changing event occurs several years later in agricultural and hunter-gatherer societies. Historical cultures celebrated menarche with elaborate rituals, and many contemporary ones still do. Though these rituals varied from place to place, two features remained constant. Elder women isolated the initiate and instilled in her that she was not to dispense future sexual favors easily, because they were extremely valuable.* The key purpose of the menarche ritual was to impress upon the girl that she was now in possession of both a great power and an enormous responsibility.

  While many menarche rituals are celebratory and loving, the ethnographic record drawn from a wide variety of cultures is replete with numerous examples of draconian ones. Among the Loango of East Africa, menstruants are confined to isolated dark huts and are prohibited from setting their foot on the ground or looking at the sun for two years. Far away in New Ireland, in the South Pacific, girls are similarly confined for four years in small darkened cages and also not allowed to touch the ground. When the symptoms of a girl’s first bleed occur among the Guaranis of South America, she is sewn into a cocoon hammock strung between two trees, with only a small slit through which she can breathe. Shrouded as if she were a corpse, the girl has to maintain a vigorous fast until her bleeding is over.4

  A postmenarche girl will, by fits and starts, begin to settle into regular menstrual cycles, which will continue, punctuated by monthly bleeding, for the next forty-odd years (interrupted only by stress, illness, starvation, pregnancy, or nursing).* Sexual intercourse during the first five years, however, seldom results in conception, because of another unusual feature of Gyna sapiens’ reproductive life history—for the first few years after menarche, anovulatory cycles are the norm.

  An anovulatory cycle is one in which the complex hormonal algorithm that drives a woman’s monthly menstrual cycle occurs on time and in the proper sequence and concentrations, the uterus sheds its lining, and external bleeding appears; indeed, every aspect of the cycle proceeds on schedule except for the one that is the cycle’s raison d’être—the ovary fails to release an egg. A few other mammalian females, notably the chimpanzee, experience anovulatory cycles during a span known as “adolescent subfertility.”† The frequency and duration in years of a young Gyna sapiens’ anovulatory cycles, however, exceed that of any other mammalian female.

  What would have been the advantage to the individuals of our species of this adaptation? Young, nubile females exhibit all the signs of potential fecundity, yet it is a sham, invisible even to the girl herself. An evolved trait enticing males to mate with what ostensibly appears to be a sexually mature female, even though her ovaries are only sputteringly active, would not seem to benefit the fitness of the species. Mother Nature, however, often works in circuitous ways. Anovulatory cycles are a boon to young women.

  A postpubescent male does not shoot blanks. His testes, unlike her ovaries, are not shy. They prodigiously pump out sperm that are more potent, swim faster, and leave the starting line in greater numbers than they will at any other time in his life. In the event that a young Lothario seduces an adolescent girl (or the more unlikely converse), or in the circumstance of rape, anovulatory cycles act as a safety mechanism to prevent the death and, ultimately, protect the health and welfare of both the girl and her potential future offspring.

  The dimensions of a female’s pelvic channel are critical to the success of childbirth. An increase in diameter of even a few millimeters can make the difference between life and death. A young woman’s pelvic circle of bone does not finish growing until she is in her late teens—four to seven years after menarche. Death in childbirth for both mother and infant is higher among adolescents than it is for mature women.* Also, postpubescent girls tend toward emotional immaturity and generally do not mother offspring well. Moreover, the likely father of her child is rarely in a position to provision her adequately, much less accept the emotional responsibility of fatherhood.

  If anovulatory cycles ensure that sexual intercourse will fail to result in a pregnancy, then one might ask why Natural Selection didn’t opt for delayed menarche. Gyna sapiens’ pelvic bones would encircle a larger channel, and her increased emotional maturity would make it more likely that her baby would survive to reach its own reproductive age. Perhaps anovulatory cycles evolved to serve another important function. I propose that they allow girls as much as six extra years to learn how boys think.†

  An adolescent male’s sexual thermostat is set on high from the first moment his puberty switch is thrown, hitting its peak in early adolescence and then gradually waning over his lifetime. Testosterone concentrates a man’s mind singularly. With the onset of puberty, male testosterone readings skyrocket to twenty to forty times their prepubescent levels. A postpubescent boy’s sexual desires nearly drive him mad as his brain soaks in a cranial tub laced with testosterone. Most men can recall with crystalline clarity the precise moment in their transition through puberty when it suddenly dawned on them that girls were not just soft boys. During an adolescent male’s waking moments, sexual fantasies are omnipresent, and nights spill forth highly exciting and disturbing sexual dreams.7

  In contrast, a female’s libido builds slowly during adolescence and doesn’t reach its peak until her mid-thirties.* A pubescent girl’s estrogen level increases to about three times what it had been prior to her menarche. Though this rise is not strictly analogous to the testosterone spike in boys, the 20–40:3 ratio gives a fair indication of how much more boys, in general, are addled by sex than girls are. In both men and women, testosterone levels have a profound effect on libido. An adolescent girl’s testosterone level rises minimally. The average male has ten times more circulating testosterone than the average female.8

  The phenomena discussed below do not apply to all boys and all girls but occur often enough that a broad generalization can be made. Whereas pubescent boys are “sex-crazed,” adolescent girls are frequently afflicted by a condition familiar to parents as “boy-crazy,” an interest not necessarily related to fantasies of sexual intercourse. Instead, teena
ge girls become obsessed with studying boys’ behavior and seek to penetrate their psychological makeup.

  An anovulatory girl learns how to be alluring as she hones strategies to entice boys. Her intense fascination extends to carefully observing the behavior of other girls and young women as it relates to the opposite sex. All her concentration has but one purpose: to understand how the man-woman thing works. It is a fine line she must walk. She desires to flummox all young males within range with her flirtations, but if she excites them too much, she might lose control of the situation. If she falls—emotionally or sexually—waiting to catch her is the safety net of her anovulatory cycles. Boys “think” with their penises, girls “think” with their hearts. Neither gender thinks with their brains.

  Anovulatory cycles amount to a free pass for several years, during which a woman-in-training can expend considerable time and energy experimenting. Mother Nature cleverly evolved a temporary tough skin to cover the surface of a female’s ovary, one so thick that it overrides the authority of her hormones, thus retarding the release of ova. This gift gives her a grace period to study the responses of males (and other females) to her dress, walk, speech, repartee, gestures, cosmetics, hairstyles, adornments, figure, and facial expressions. As she gradually gains an appreciation of the power she has over a male, early on, she also grasps the leverage inherent in the word No!

  Another safety factor operational at this period of development I shall call “pubescent reverse sexual dimorphism.” Sexual dimorphism, remember, is the disparity between the size of the male and the female of a species. Humans fall somewhere in between the most sexually dimorphic species and the least. Men are about 8 percent taller and 20 percent heavier than women—except for one brief span during which girls are larger, taller, heavier, and in many cases as strong as or stronger than boys of the same age. As any adult chaperoning a middle-school dance can attest, eleven-to-fourteen-year-old girls are, on average, a head taller than their male peers. This period, coincidentally, circumscribes the years when anovulatory cycles are most frequent. No other species exhibits the typical human adolescent growth spurt.9 And no other species features so pronounced a reversal of sexual dimorphism.

  The physical advantage men have over women, enabling them to impose their will through superior strength, is absent during the one period when they are least able to control their urges. Should a twelve-year-old boy get carried away and try to satiate his sexual urge by force, Mother Nature has conveniently equipped the girl with the physical means to defend herself.

  Anovulatory cycles, differential sizes, and the gaping disparity in libidos are factors that allow an adolescent female to “get up close and personal” without risking pregnancy. They allow her to hone what men, in their befuddlement, refer to as “women’s intuition.” This “sixth sense” will be of paramount importance to her. First, it will help her determine which future suitor might be the most steadfast and successful in supplying her with iron and other important resources. And, second, it helps her learn how to influence males to do her bidding. A woman who fails to learn how to choose wisely and influence men endangers both herself and her unborn children.

  Aware of the quirk of anovulatory cycles, many ancient cultures held a very liberal attitude toward sex among their young people. Accounts from Mesopotamia, ancient Egypt, and classical Greece record young people indulging in unbridled sexuality during fertility rites and certain religious holidays. Herodotus tells of young girls serving as sexual temple priestesses. After several years of duty, they would leave to marry and begin families. There apparently was no social stigma attached to this service.10

  A number of isolated indigenous cultures throughout the world (for example, the Trobrianders, in the South Pacific, and the Mangaians, in the southern Cook Islands in central Polynesia) continue to sanction, and even encourage, matings among their unmarried youth.11 If pregnancy were a common consequence of these activities, no doubt elders would discourage the practice. The current rise of teenage pregnancies may not be due to the obvious. Perhaps modern girls are having sex as frequently as did their predecessors in older cultures, but the rise in their pregnancy rates may be due to a sharp reduction in anovulatory cycles.

  Some unexplained factor in modern societies has greatly reduced the incidence of cycles without an egg in teenage girls, and as a result, they become pregnant at an earlier age and more frequently than their sisters in earlier historical periods. Some scientists have speculated that high-fat diets have brought about this change. Others claim it is the increased estrogenic compounds in our environment, such as pesticides, other chemicals, or the high estrogen levels in commercially processed cow’s milk. Another intriguing hypothesis fingers the massive increase in artificial lights, which has upset the natural timing of sunlight and moonlight. No one knows with certainty.

  I suspect that another key factor stimulating earlier menarche and diminishing anovulatory cycles has been the authorities’ recognition of the importance of iron in the diet of females. Iron-fortified foods consumed by children and teenagers, along with a consistently high meat diet, have increased their young bodies’ iron stores. This increase, combined with adequate stores of fat, has signaled the feedback controls in the brains of these young girls that it is now permissible for pregnancy to proceed.

  Males do not experience anything so dramatic as menarche. Yet, prior to the advent of modern society, diverse cultures commonly created an initiation rite for boys crossing the threshold to manhood. The fundamental difference between the male and female transition into puberty is that a man must “prove” himself worthy of manhood, whereas a woman has only to begin menstruating to be accepted as a woman. Although some societies have rigorous menarche rituals, none exist in which a young girl can “fail.” By contrast, among the Plains Indians male-initiation rites were so challenging that boys were stratified according to how well they passed the tests; the highest achievers were elevated to the warrior caste.

  Uniformly, male initiations, designed by male elders, tested a young man’s mettle. Hunting and warrior societies especially prized fearlessness in their young men. They inculcated values important for a future hunter who must work in concert with others. Trials of skill, strength, stamina, courage, obedience, resourcefulness, cold-bloodedness, and the ability to withstand pain and privation were common initiation elements. As if to mimic menarche, many hunter-gatherer and agricultural societies incorporated bloodletting into the ritual.* The ultimate goal of ancient male-initiation rites was to encourage initiates to be brave and willing to take risks.

  Fortuitously, Natural Selection created ideal conditions to ensure that adolescent boys would seek thrills by flirting with danger. The reason parents often have occasion to screech at their young sons, “What were you thinking?” is the acute imbalance that exists in pubescent boys’ brains—insufficient myelin combined with exceedingly high levels of testosterone.

  Myelin is a gigantic molecule that binds fat globules within a lattice of protein. Once formed, it serves to sheathe individual neurons, the information-transmitting cells of the nervous system. Myelination is the process by which a human brain’s nerves receive their myelin coatings, the function of which is similar to the insulation used on copper wires. Disparate areas of the brain and the peripheral nervous system myelinate at different ages during growth.

  Both nerves and wires conduct electrical currents that generate electromagnetic fields extending into the surrounding space. These fields will, in turn, activate currents in otherwise dormant wires or nerves nearby. This is the principle behind radio and television transmitters and receivers, dynamos, and transformers, and as with these man-made devices, “interference” (or static) in nerves or wires is a potential problem. To protect signals from corruption by neighboring electromagnetic fields, each individual nerve is encased in insulating material.

  In the electrical industry, this substance is the familiar plastic or rubber that sheathes the wires of appliances. In the bra
in and peripheral nervous system, the insulating substance is myelin. The fetal brain contains very little myelin. Evidence of a newborn’s lack of it is apparent in the Moro reflex.* Hands clapped loudly near a newborn will startle it. The sharp sound sets off a chain reaction, so that the infant responds as if every nerve in its body had been activated. The newborn adopts a signature open-armed grasping manner, as if reaching out to embrace its mother for protection.

  As an infant’s brain grows, it steadily lays down myelin around its nerves. In general, myelination proceeds from bottom up, back to front, and right to left, and takes some twenty-odd years to complete.

  If we are to understand better the consequences of this pattern for relations between the sexes, a brief detour into brain development is in order. Neuroscientist Paul MacLean introduced the concept of the triune brain in 1973.13 According to MacLean, the human brain consists of three components derived from different evolutionary periods. Arranged in a vertical hierarchy, each stratum sits atop the older one.

  The oldest brain component—the brain stem—was inherited from our dinosaurean ancestors. This reptilian brain responds to stimuli in a rigid, programmed fashion and contains the primitive instincts behind basic survival behaviors. Above the reptilian brain sits what MacLean calls the “paleomammalian brain,” the one humans inherited from our mammalian ancestors. Comprised primarily of the deeper layers of the occipital, parietal, and temporal lobes, this stratum (more commonly called the limbic system) enlists emotions to evaluate current sensory input and will often cross-check against past emotionally charged situations.