Liberated Christians
Cyber Swing/Polyamory Resource Center
Promoting Intimacy and Other-Centered Sexuality



The Uniqueness of Human Female Sexuality vs Other Mammals
Highlights of Sex, Time and Power
By Leonard Shlain

Unique - Women's Hidden Ovulation
Unlike most other female specious females do not advertise their ovulatory burst. With very few exceptions, other species' females have a distinct period of sexual receptivity during which they experience a powerful instinctual drive to mate. To the males of her species, a female emanates a distinctive "green light," whether olfactory, visual, auditory, gestural, or some combination thereof. These episodic heights of female sexual desire are exquisitely timed to coincide with her ovulation. Previously uninterested males are alerted by her attention-grabbing signals.

Estrus, as this upsurge is called in female primates, promotes harmony between the sexes. When both male and female are equally excited about mating, it is likely that they will have an amicable and mutually rewarding encounter. Obviously, a considerable benefit accrues to the species if mating occurs in synchrony with ovulation. Sperm meets ovum, and conception occurs. Eve's daughters, however, lack this most basic sexual semaphore, having replaced it with concealed ovulation. Human ovulation is so cryptic that most women remain unaware when, precisely, their eggs have departed from their ovaries.

Unique - Women's Constant Sexual Ability
Further obscuring the timing of her ovulation, the human female acquired the potential to engage in sex, if she desired, 365 days of the year, during pregnancy, lactation, menstruation, and even after menopause. [Bonobos, a kind of chimpanzee, also engage in sex nearly continually. Nevertheless, females signal through smell and visual displays when they are in estrus, even if that estrus lasts two weeks of their six-week cycle. Ninety percent of bonobo sexual penetration take place within their estrual period.]

An alternative way to state this unusual condition would be to say that the human female does not experience a distinct period of estrus because she is in a state of constant estrus. Precious few other species' females could hold a candle to the human female in this department. No other species has so definitively uncoupled sex and reproduction as the human line. Since sex is so intricately intertwined with reproduction in the other three million sexually active species, what would have been the reason that Natural Selection abandoned this successful strategy in humans?

Unique - Women's Prolonged Orgasmic Response
Another innovation: Some human females experienced a prolonged orgasm capable of multiple sustained repeats. And yet no nonhuman female, in her observable behavior, comes anywhere near to attaining the heights of sexual pleasure manifested by a woman in the throes of her orgasm.

The male's orgasm, in human and other species, is a necessary component of his ejaculation. It is followed by his rapid withdrawal and prompt disengagement. Only in the human can the female notify the male through vocal or body language, after the completion of his delivery call, that she is not finished, and that she expects him to continue until further notice.

Unique - Variety in Human Sexual Positions

Moreover, the variety of sexual positions used in human intercourse exceeds that of virtually all other species. Women became the first land females to habitually copulate face to face with their partners, and they became the first females to increasingly take advantage of an alternative position: mounting a supine male. [Stump-tailed monkeys and bonobos also use these positions on occasion, but a male mounting from the rear of the female remains their preference.]

Unique - Human Foreplay
Another feature of human sexuality is the prolonged period of sexual foreplay that occurs prior to penetration. Many other species engage in elaborate mating and courting rituals. However, when they finally get down to business, sexual foreplay is virtually nonexistent. The human male, in contrast, seems to have grasped the key fact somewhere along the line that it was in his best interests to expend considerable time and effort preparing his partner so that she, too, could experience pleasure. Concern for the pleasure of the female he is preparing to penetrate is not a motive that one would impute to the amatory repertoires of any other species' males. [Again, male bonobos also exhibit this behavior to a limited degree, and chimpanzee males will groom a female who is pregnant or lactating in the expectation that when she comes into estrus again she will be more receptive to him.]

Unique - Women's Blood Loss
Biologists estimate that there are between ten million and thirty million different species of life-forms on earth today. Of these, four thousand are mammals. Only one among the four thousand experiences significant blood loss on a regular basis. If conception does not occur, a fertile human female sheds the lining of her uterus along with approximately forty to eighty milliliters (several tablespoons) of blood every four weeks. A few other mammals--for example, hedgehogs, bats, shrews and elephants--show signs of menses, but for all of them it is a relative nonevent. Primatologist Alison Jolly estimates that there are approximately 270 different species of primates. Only thirty-one species of primates menstruate. All of these but one, a human, lose an insignificant quantity of blood.

Unique - Menopause Period
Another anomaly of the human female's sexual life cycle is her menopause. A woman stops ovulating at an earlier point in her life than any other female mammal, while coincidentally acquiring the distinction of becoming the longest-lived terrestrial mammal. [Some bowhead whales have been estimated to live to 150 years.]

If she avoids maternal mortality and other female causes of an early demise, a woman can on rare occasions achieve a life span exceeding a hundred years. The human female was clearly built to last. At present in the United States, she outlives her male counterpart by an average of six years, while attaining an average life span of eighty-three years.

A postmenopausal woman possesses a longer period of life during which she is incapable of conceiving a new life than any other female mammals, even though she remains quite vigorous for most of these years. With very few exceptions, other mammalian females ovulate right up to the day they die. And a woman stands in stark contrast to a man, who, despite advanced age and many infirmities, usually can generate viable sperm far into his dotage. Another baffling feature of human menopause: Despite the early cutoff in their reproductive faculty, some menopausal women report an increased libido. If the purpose of sex is the continuation of the species through reproduction, why, only in the human line, did early cessation of ovarian function combine with longevity and increased libidinous desire?

Unique - Women's Willpower
The innovations distinguishing the human female from other mammalian females mentioned thus far pale when compared with her most spectacular new feature. She became the first species who possessed the willpower to refuse consistently to engage in sex around the time she was ovulating. For that matter, she was the first animal of either sex , of any species, capable of deciding to remain celibate if she so desired.

This resolve is the heart of Response W. This is the gift Natural Selection bestowed upon her for having to endure Factor X, high maternal mortality and painful childbirth. It is something that had heretofore never existed in the animal kingdom. Philosophers call it Free Will. And herein lies the crux of relations between the sexes. African Eve and her daughters developed the determination to choose consciously a course of action that overrode the instinctual circuits that drive every other species' females to copulate when they ovulate. Females of some other species may be able to choose which male among multiple suitors upon which they wish to confer their favors; an occasional female of any species may decide not to mate with anyone or at any time. But the human species was the first in which all the females evolved the capacity to decide consciously to refuse to mate during any one ovulation or all the time.


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