The Sexual Male, part two: Are We Not Boys?

IN THE SECOND OF A SERIES OF REPORTS ON THE SCIENCE OF MALE SEXUALITY, WE EXAMINE THE DELICATE AND STILL-MYSTERIOUS PROCESS THAT CREATES A BOY AND YEARS LATER TRANSFORMS HIM

n May 25.1983 Or. Mary Calderone took the stage at the Sixth World Congress of Sexology in Washing­ton. D.C. to talk about an ultrasound image she had been given that clearly showed a 29-week-old fetus with a hard-on. A sonographer in New London, Connecticut had first recorded prenatal erections five years earlier-all seven of her subjects were sucking their thumbs-but Calderone hoped to put the discovery in context. A pioneering sex educator (she argued in her 1970 Playboy Interview that rudimentary sex education should begin in kindergarten), Calderone saw fetal erections as firm evidence that we are sexual beings from the beginning. Ultrasound technicians would later observe erections in fetuses as young as 16 weeks. In other words, a man gets wood soon after blood reaches his groin and months before he draws his first breath.

YOU CESTATE LIKE A GIRL

The making of a male starts simply enough. If the head of the sperm that fertilizes a woman's egg contains a Y chromosome, it joins with an X chromosome she supplies to create a boy (XY). If the sperm carries an X, they form a girl (XX). Beyond that, much of the process remains a puzzle. In 1990 scientists discovered a gene on the Y chromosome called SRY. which gets the male cascade started, although it has been suggested that its role may be only to suppress a second, as yet undiscovered female gene dubbed Z. The next step is the activation of the gene Sox9. which is present in both genders but sees action only in males. A third gene. Fgf9, then cranks up the volume of Sox9, rattling the windows and eventually leading to the creation of testicles. Cell biologists at Duke University discovered last year that Fgf9 has another vital function: It turns down the volume of a girl-making gene known as Wnt4. If 5RY isn't present, Sox9 and Fgf9 remain quiet and Wnt4 (which may well be the elusive Z) takes over, resulting in the formation of ovaries.

Those are the basics. But there are exceptions, such as the rare man who doesn't have a Y chromosome. He is XX. a genetic female, yet still grows balls. How can this be? In some cases SRY is present on the X chromosome contributed by the father. In others Sox9 initiates the march toward maleness, although the beat isn't as loud and often results in men who can't produce sperm. This past October a team of Italian scientists announced the discovery of yet another part of the equation. While examining four brothers who don't have an SRY among them, researchers found each had a mutated Rspoi. a gene that appears to team up with Wnt4 to stifle the male-making power of Sox9. In this case, Wnt4 waited for backup that never arrived, and four sisters became four brothers.

There are many more genes along the route of the Cajones Express and a lot of chatter back and forth. The conversation continues until about the seventh week of your existence, when the signal finally reaches the

sexless blob of tissue known as the gonads. Its cells are believed to be bipotential, meaning they aim to please. If the signal is a grunt, the cells gurgle and pop and reassemble into testes. Initially perched near your kidneys, these two balls will churn out the pow­erful hormones that will craft your penis, scrotum and everything else. Alfred lost, an endocrinologist working in Paris shortly after World War II, first demonstrated how important these androgens are in creating a man by cutting off the microscopic balls of fetal rabbits-a feat in itself. Even though the rabbits still had a Y chro­mosome in each cell, they developed into fully functional females capable of giving birth. This and later research persuaded many scientists that female is the default gender-Adam comes from Eve's rib. To produce a boy, nature must break the mold with a bath of testosterone. This premise has leaked into gender politics, with commentators portraying males as either enhanced or deformed versions of the base model. But as researchers learn more about fetal development, many reject both views as incomplete. For ovaries to form, a number of active processes are required; it's just that scientists know even less about them than what goes into making a boy. If nothing at all happened, you wouldn't end up as a girl but as a miscarriage.

A more potent fact is that both male and female genitals develop from the same tissue. It's much like an episode of Iron Chef: two meals created from the same ingredients. In a boy the gonads develop into the testes and sperm tubes; in a girl they become the ovaries and its tubes. The tissue that becomes the Denis and scrotum develops in women into the clitoris, which has

been found to extend three or four inches into the body. The foreskin Is the clitoral hood. The urethra is homologous to the smaller lips of the vulva; the scrotum is the larger lips. The Cowper's gland, which produces precome, is the female Bartholin's gland, which contributes to vaginal lubrication, and the male prostate is the area in women commonly known as the C-spot. Both genders have nipples because they develop before the great divide. Do you see where this is heading? While having vagi­nal intercourse, you are penetrating an inverted version of yourself. The philosophical notion that sex unites parts of a whole and makes us one fits nicely with reproductive biology. Jost's experiments with rabbits led scientists to wonder whether slicing the balls off a human male fetus would cause it to develop into a fully functional female. Of course such an experiment would be barbaric, but in the 1950s scientists discovered mutations that seemed to have done it for them, producing women who appear from every angle to be female but are genetically male, with a Y chromosome in each of their cells. An XY woman begins her development in the womb as a male complete with testes but changes course because her cells cannot absorb male hormones. The fetus has to do something with the excess

androgens, so it converts them to the primary female hormone, estrogen. The result is a tall woman with small hips, large breasts, clear skin and great hair. Indeed, the first XY women identified in the 1950s were all stewardesses or models (and perhaps pin­ups), and it's the sort of build that has invited speculation about a number of Hollywood actresses. Tests conducted before the 199G Olympics revealed that eight of the 3,387 female athletes were XY, raising the question of whether having a male chromosome provides women with a competitive advantage. The XY women, who were not identified, were all allowed to compete.

The discovery of XY females especially intrigued lost because they are always sterile, with shallow vaginas that lead nowhere. The male rabbits he castrated in the womb developed ovaries and every other organ needed to produce offspring; XY women, who keep their testes, do not. Years earlier Jost had implanted testicu-lar fragments into female fetal rabbits before sex differentiation and found the animals became male inside and out. Simply inject­ing testosterone, however, led only to male genitalia. He concluded that the testes must produce not only testosterone to mold the penis but a second hormone that switches off a man's inner girl-that males are not only masculinized but defeminized. And he was right. Each embryo starts its journey with two carry-ons: the Mul-lerian ducts, which become the uterus, upper vagina and fallopian tubes; and the Wolffian ducts, which become the tubes in which your sperm are created and carried to the penis. As you develop, your balls produce three crucial hormones. Testosterone crafts the penis and helps mold the brain. Another hormone causes the

testes to be pulled along two tem­porary canals by the gubernaculum (a ligament named for the rudder on a Creek ship) and dropped into the scrotum. And a third substance, known as Mullerian inhibiting hor­mone, or MIH, makes your Mullerian ducts shrivel. In fact, you're sitting on your discarded pussy right now-it rests behind your scrotum and under your prostate. The power of MIH can be seen in those rare cases when a fetus doesn't produce enough and a man is born with a womb.

EARLV AROUSAL

Since the discovery of prenatal erections, in 1978, scientists have learned much more about them. In the most ambitious fetal-erection study of all time, Japanese research­ers checked 12 full-term boys every minute for an hour and reported that 42 percent had at least one erection, with the longest lasting 17 minutes. Another study revealed that fetuses have regular erections during deep sleep, just as they will throughout their lives. Scientists believe these sleep erections, which occur in adults every 90 minutes or so, are a systems check by the brain, which never knows when the fire will need wood-even inside Mom.

Many of the 185,000 boys born each day have erections as they emerge. It's an exciting time. That

infants get hard-ons rather frequently has never been a secret to new parents, but it wasn't until 1937 that a Yale professor of child development documented precisely how often they occur. With the help of three assistants, he observed nine newborns in a maternity ward for 10 days and counted 1.663 events. Since a boy doesn't pro­duce sperm until puberty, why does he have or need the ability to get hard? Perhaps these early erections occur simply because everything is in place. Or they may be calisthenics designed to tone and maintain muscles and nerves that will later be used for reproduction. Whatever the reason, a boy soon discovers that his arms are just long enough to provide an assist now and then. This even occurs in the womb: Obstetricians have observed fetuses of both genders touching themselves for min­utes at a time. It's a special moment in a boy's life, the first in a lifetime of gropings. After observing 170 mothers and their babes, Dr. Rene Spitz reported in 1949 that the infants with more-nurturing mothers touched themselves more often. The more you are loved, the more you love yourself.

Scientists have long debated at what point a child's reflexive diddling can be called masturbation. Some researchers speculate the threshold is crossed when a boy is able to stroke himself long enough to elicit a response elsewhere in his body. Based on observations of 66 infants and toddlers through one-way glass, two New York psy­chiatrists concluded that the first acts of "focused pleasure" are reflected in the child's expression of excitement, flushed skin, rapid breathing and perspiration. (The research is described in their book Infantile Origins of Sexual Identity.) Alfred Kinsey felt you couldn't call it masturbation until there is evidence the child anticipates "reaping an erotic reward." Regardless of what's going on inside their heads, many preschoolers quickly master the mechanics. Dr. Milton Levine of New York Hospital-Cornell Medical Center, one of the few physicians to address the issue in print, reported in 1951 that between the ages of two and a half and five many boys in his care had learned to wrap a hand around their erection and knead it. Further, parents told the pediatrician their sons would lie on their stomachs and writhe on the floor, even while absorbed by the television. "This is reminiscent of the early rocking of infants," Levine observed, "for these boys lie on their stomachs with their hands at their sides, raise themselves slightly from the bed or floor and propel themselves forward and back." This behavior is sometimes misdiagnosed as a medical problem even today because it's not something parents expect or perhaps want to see. In 2005 four neurologists reported on 12 pre­schoolers-all girls-brought to a Rochester, New York clinic for "movement disorders." After investigations that included videotaping the children, the researchers concluded the girls were engaged in "gratification behavior," a term the doctors found went down easier with parents. They noted that the distinction between masturbation and sei­zures can be difficult to recognize because both involve a glassy-eyed, fixed gaze. But the conditions can be distinguished by the fact that the child does not become annoyed when interrupted during a seizure.

If scientists are tentative in approaching self-stimulation, they are even more cautious in asking whether prepubescent boys are capable of orgasm but simply lack the motivation or coordination to make it happen. (There has been speculation that male thrusting during intercourse is reflexive and occurs on occasion in tod­dlers when they feel amorous.) If you trust the memories of college students, early climax does occur. In a survey of 303 students conducted by Dr. John Bancroft of the Kinsey Institute and two colleagues, 12 percent of women and 13.5 percent of men recalled having their first orgasm before puberty, with the average age among these groups being 8.5 years for females (the earliest at the age of four) and 9.6 years for males (the earliest at the age of five). In easily the most controversial finding in his 1948 best-seller. Sexual Behavior in the Human Mole. Kinsey reported that infants as young as five months can reach climax, appearing to have the same physical reaction as adults-flushed skin and tightening muscles, followed by a sense of calm. However, Kinsey did not report that his sole source for this information was a child molester who kept meticulous records of his abuse of 28 babies and similar numbers of children of every age up to 15. The man claimed that the younger the child, the more easily the boy seemed able to achieve multiple orgasms.

This area of Kinsey's research "should properly be treated with great caution," Bancroft warns on the Kinsey Institute website. "The data leaves us with some fundamental questions, and not surprisingly, there has been virtually no further evidence to answer them." The questions include, he says, whether the ability to climax before puberty influences later sexual development and what mechanism makes multiple orgasms, if they do occur in preteens, virtually impossible for boys after they mature? What is normal?

CHILDHOOD INNOCENCE

That has never been an easy question to answer. Over the past century Americans in particular have embraced the notion that children are asexual until puberty-or marriage. Some of the blame for this fallacy lies with Sigmund Freud, who in 1899 famously theorized that a boy passes through oral, anal and phallic stages of development before shutting down his libido at the age of five. (Decades later the German sexologist Ernest Borneman proposed a pre-oral phase he called

cutaneous-from the Latin for "skin"—during which the entire surface of an infant is his primary erogenous zone.) A boy remains asexual until puberty, Freud wrote, because he comes to realize he desires his mother but fears his father's violent reaction should he find out. Although Freud's latency period has been shown to be bunk, early sexual development remains a sensitive topic. To determine what is normal, U.S. researchers must rely largely on the memories of adults or the observa­tions of mothers, although scientists in Europe have quizzed preschoolers directly about what they know. Toddlers first under­stand there are two genders, then learn that gender is deter­mined by more than hairstyle or dress, and finally advance to games of doctor or "let's pull down our pants" (still fun as an adult). In recent years biologists have stepped in, arguing that the slow burn of sexual maturity flames up as early as the age

of six, when the adrenal glands begin releasing more androgens into the brain. Known as adrenarche, this is a lapping of waves before the tsunami. Adrenal puberty is responsible for acne out­breaks, body odor and the growth of pubic and underarm hair, as well as our first erotic feelings and fantasies, such as a crush on a teacher. "Freud had a word for the moment when you realize you are attracted to girls or, in some cases, boys," says sexologist William Granzig. "He called it sexual cathexis. You don't know what to do with this attraction at the age of five, but the particu­lar culture in which you are raised will educate you about what is good and bad." This cathexis occurs at such a young age that homosexuals, when asked when they first knew they were gay, invariably respond, "I've always known." (Heterosexuals would say this too, but no one asks.) The influential psychologist John Money suggested that children very early on begin developing "love maps" that determine their later attractions and sexual appetites. According to Money, these maps are most vulnerable to damage by repressive adults when children are between the ages of five and eight.

The transformation from boy to man is well under way by the age of 10, when the typical adolescent has the same amount of testosterone as some adults and as much as 20 times more than younger children. In fact, the age of 10 is recognized as the start of adulthood in many cultures, includ­ing the U.S. for most of its history. (It was the age of consent for girls in most states until the 1880s.) Even if a child hasn't

transformed physically by 10, parents sense something has changed. This is when boys learn the mechanics of intercourse, when they can first comprehend a joke about the snake in the grass. Usually children learn about sex not from parents but from older classmates, most of whom don't have Ph.D.s in human sexuality. According to one survey, fewer than half the parents of kids under 12 had spoken to them about sex. com­pared with 91 percent who had discussed alcohol and drugs. Plus, a third of the kids whose parents said they had talked about sex with them couldn't recall the conversation.

SEPARATION ANXIETY

At the same time hormones are shaping our brains to nego­tiate a lifetime of mingling, boys and girls part like the Red Sea. Children begin organizing by gender early. For instance,

one study found preschoolers spent three times more of their playtime with classmates of the same sex; by the age of seven it's 10 times as much. The split is most pronounced during the final years of elementary school. In the 1980s sociologists Barrie Thorne and Zella Luria observed this firsthand when each spent a year hanging out with nine- to 11-year-olds at schools in California, Michigan and Massachusetts as part of a joint study. Whether on the playground, doing schoolwork or standing in line, boys and girls mostly kept to their own. The girls shared intimate secrets and shoulders to cry on. The boys bonded by breaking rules, yelling "Shit!" or "Fuck!" as they played sports, for example. After ejaculating these words, boys would grow flush, wipe their hands on their jeans and look guilty. There are a number of entertaining hypoth­eses for the gender split, including that boys need to devalue femininity as they struggle to separate from their mothers. But Thorne, a professor of sociology and women's studies at the University of California at Berkeley, says the structure of American schools, which segregate kids by age, is the most powerful influence. "The relationships between boys and girls in the neighborhood or at church, where older and younger kids mix, are usually quite different," she says.

This is also the time when boys accuse one another of "lik­ing" the most or least popular girls. They begin to chase girls on the playground, retreating after each foray to the safety of their island of friends. Teachers are (continued on page 130)

SEXUAL MALE

(continued from page 104) less alarmed by these pursuits among younger children, but by fifth and sixth grade many girls have breasts, which appear to adults to eroticize the game. Thome says this time is full of "moments of reframing" for boys. She recalls a girl who had been caught by a boy who pinned her arms to her sides: "She looked at him and said, 'You're hugging me,' and he let go immedi­ately." Playground "rituals of pollu­tion," a.k.a. cooties, are also interesting in that girls are far more often seen as afflicted. For boys, being touched by polluted (sexual) females becomes fraught with both danger and pleasure. In an act of betrayal, a boy may hold down a friend so he can be kissed.

As the hormones in the body and brain increase from a trickle to a flood, these antics come to an end. A boy's sense of identity as a male, his sexual response and his ability to form dyadic relationships—elements Ban­croft suggests develop relatively inde­pendently—start to merge. Youngsters begin to go steady, tentatively at First, with infatuations that last only days or weeks. Rather than sharing found porn with their friends, boys retreat for private reflection. Slow dancing is introduced at parties, and first kisses are exchanged, prompting what for a boy feels like the hardest erection of his life. When I had my first lip-lock, at the age of 13, my corduroys nearly burst at the seams. Where does that energy go?

THE BIG CHANCE

Most men remember puberty as an uncomfortable time when their bodies fit like a bad suit, their voices cracked due to the thickening of their vocal cords, and girls ignored them in favor of the cooler ninth-graders, who were themselves ignored in favor of cooler seniors. You want to give that kid you once were a hug. Hang in there, buddy. He is an alien—half boy, half man. Adrenal puberty (which occurs only in humans and apes) has given him the desire to reproduce, and now gonadal puberty provides the means. For the typical boy, the renovations directed by the testicles begin at the age of 1 1 and a half—nine months after gonadal puberty begins for the average girl—but can start as early as nine or as late as 15. Some studies have found that boys who mature early have more self-esteem, success and lovers, while other research suggests they are more likely to become juvenile delin­quents. So you can't win.

The drama of gonadal puberty lasts two to four years. As increas­ing amounts of testosterone circulate through the bloodstream, the downy

hair on your genitals thickens and expands. Follicles come to life on your neck, face, chest and back. You become stronger. About 50 percent of boys experience a temporary growth in breast size due to a surge of the hormones that cause the same effect in girls (with more pleasing results). You get sleepy later at night and have more trouble waking up. Your balls become five to 10 times larger as the tubes inside them grow in diameter and your germ line begins creating sperm at a blistering pace. Your penis length­ens, and your scrotum darkens. Dur­ing late puberty you grow an average of 3.75 inches a year. Your body moves toward a ratio of 40 percent protein to 15 percent fat. (A girl's ratio is 23 percent protein to 25 percent fat.) It also begins to produce an abundance of red blood cells, meaning more oxy­gen can be distributed to burn energy. You work up quite an appetite. And of course the random hard-ons begin, popping up like automatic timers in a turkey. You can never predict what will set them off. In a study published in 1943, Glenn Ramsey of Indiana University asked 291 boys to list things that had given them erections. They mentioned the usual suspects, such

as dirty talk, nude women, porn and fantasies. But half the boys, mostly the 10- to 12-year-olds, also men­tioned carnival rides, airplane rides, war movies, being late to school, book reports, riding at high speed in a car, playing a musical solo, fast elevator rides, being chased by police, big fires, electrical shocks, sitting in class, seeing their name in print, expecting a show­down with a bully, facing a long flight of stairs, looking over the edge of a building, hearing an adventure story, singing the national anthem, anticipat­ing a scolding, taking a shower, riding a bike and getting a report card. Other than that they had no problems.

By the age of 12 or 13 everything is usually in place for you to fulfill your biological duty. In many cultures and eras you would get started soon after your first ejaculation (semenarche). One survey of 186 preindustrial soci­eties found that most teens married within two to four years of reaching puberty, but an American adolescent typically waits as long as 15 years, which leaves plenty of time for mas­turbation. Even if you avoid touching yourself, the expanding line of sperm will escape in your urine or through nocturnal emissions—wet dreams.

These orgasms, created by your brain without benefit of stimulation, are a demonstration of who runs the show.

THE PULSE OF MANHOOD How does your brain know it's time for Extreme Makeover: Homeboy Edi­tion} Everyone has ideas. It may have an internal clock that counts down the days. Or perhaps the body sends a sig­nal when it reaches a particular weight or fat-muscle ratio. Puberty may begin the moment a boy first consumes more calories than he needs to survive. It has even been suggested that teenage girls send a signal—a scent, perhaps—that says "Come and get us." It could be a combination of events. Whatever the trigger, the transformation corresponds with the secretion in the hypothalamus of gonadotropin-releasing hormone (GnRH), which pulses like a heartbeat every two or three hours during the day and more frequently at night as you sleep. GnRH is of interest to only a single tiny part of your body—the pea-size pituitary gland positioned above the roof of your mouth. Once activated, the gland releases its own specialized hor­mones into your blood that turn on the gears in your testicles. That's puberty in a nutshell. It's a delicate operation,

at least inside your head. GnRH is produced by a cluster of just 1,000 neu­rons (among a hundred billion) that are created near your sinuses and then march across your forebrain. As mea­sured by GnRH pulses, your sexual maturation begins soon after, while you are still in the womb, continues until you're about a year old, then slows or stops (it's not clear which) for eight to 12 years. "This break is probably adap­tive," explains neuroendocrinologist Tony Plant. "It evolved to give boys time to develop before being exposed to the powerful effects of testosterone, so they can acquire culture and such. The time off is useful for females because they cannot reproduce until their pelvic gir­dle has grown to a size that can accom­modate a newborn's head."

Scientists who study puberty have been working backward, hoping to eventually locate the signal that activates the GnRH pulse. In 2003 researchers in Paris and at Harvard took a small step for man­kind when they independently identified a puberty gene, GPR54. Both research teams discovered families in which a number of adult siblings and cousins had never reached puberty; each had a defective GPR54. In 2005 a team led by Plant documented the role of another gene, KiSS-1, which produces a protein, kisspeptin, that binds to and switches on GPR54. In experiments with adolescent rhesus monkeys at his lab at the Univer­sity of Pittsburgh, Plant found he could induce puberty by injecting kisspeptin and waiting 30 minutes.

Once GnRH is pulsing again and gonadal puberty is under way, sub­stances such as human growth hor­mone, leptin, insulin and melatonin regulate the transformation. (A recent Italian study found that the more time a child spends in front of computer

and TV screens, the less melatonin he produces, suggesting he may mature more quickly.) It's obvious when a boy physically becomes a man, but with the advance of medical technology, sci­entists are now able to observe what's in his mind at the same time. In 1990 Dr. Jay Giedd, chief of the Brain Imag­ing Center at the National Institute of Mental Health, launched an ambitious experiment: His lab began scanning the brains of 1,000 children every two years as they grew into adulthood. These images document a period of explosive growth that occurs in the average girl at the age of 11 and the average boy at 13.5, followed by a careful pruning of unused connections. (A similar period of growth and pruning begins in the womb and continues until a child is about 18 months old.) The expansion is particu­larly intense in the prefrontal cortex, which allows us to prioritize, think in the abstract, anticipate consequences and control impulses. It has been called the area of sober second thoughts. It's also the part of the brain that processes facial cues and body language. While the ability to interpret faces is in place shortly after birth, it's not until your 20s that you become adept at spotting subtle differences, such as those between fear and shock or recognizing that what a woman says isn't necessarily what she means. ("Of course I don't mind if you go to that bachelor party.") Giedd has found that many changes to the brain have nothing to do with the hormone rush of puberty but appear to be con­trolled by genes that are activated by some unknown trigger. "Two or three dice are thrown," Giedd says. The brain becomes increasingly elastic during this period, which may help us adapt as we are expected to fend for ourselves for the first time. Giedd also notes how a

boy's approach to the world changes simply but profoundly. "Before mak­ing any decision, his brain starts asking. 'Will this lead to sex?' It's a huge switch and predicts an enormous amount of behavior in mammals in general."

Some evidence suggests that the age at which children reach puberty has grown dramatically younger over the past few-centuries. It is easy to document this trend in girls because sexual maturation is marked by their first period. With boys, scientists are left to guess when the sperm factory kicks on by measur­ing testicles or scanning for pubic hairs while digging through historical records for benchmarks. For example, when J.S. Bach directed the Leipzig boys' choir from 1723 to 1750, the voices of the singers typically did not break until the age of 18. By 1959 the average was 13.3 years. More recently, Giedd and other scientists have concluded that the mind does not mature until the early 20s and perhaps as late as 25. Together these developments put the coming of age of the body and brain a decade or more apart. "It's like turbocharging an engine without having a skilled driver," says Dr. Ronald Dahl, a professor of psy­chiatry and pediatrics at the University of Pittsburgh. Some people argue that this disparity is a good reason to keep teenagers ignorant of sex. because they are more likely to take chances that lead to pregnancy and STDs. But according to a team of social scientists who com­pared teen pregnancy rates in the U.S., Canada, the U.K., Sweden and France, this argument fails to account for the fact that teens outside the U.S. have lots of sex and don't get pregnant nearly as often. A key difference is that they are much more likely to use contraception.

Despite the perception that Ameri­can teenagers are fucking like rabbits, most boys don't have intercourse until their final year of high school. In an anonymous national survey conducted in 2002 of 5,700 male high school stu­dents, 56 percent of the 15-year-olds said they had not yet had intimate sex­ual contact. By the age of 17, 36 percent still had no experience, but 52 percent had gotten a blow job, 47 percent had experienced vaginal intercourse, and 13 percent had experimented with anal sex with a female partner. The trip around the bases, from kissing to caressing breasts to genital petting to penetration, typically takes about two years (not necessarily with the same girl), with each stage viewed as a rehearsal for the next. Indeed, some researchers have found that having a girlfriend has more influence over whether a boy has sex than religion, parenting or peer pressure. To para­phrase Chris Rock, you're only as faith­ful to abstinence as your options.

A MORE POTENT FACT IS THAT BOTH MALE AND FEMALE GENITALS DEVELOP FROM THE SAME TISSUE. IT'S MUCH LIKE AN EPISODE OF IRON CHEF: TWO MEALS CREATED FROM THE SAME INGREDIENTS.