For years, scientists have been debating the function of female
orgasm. Nowthey've finally figured it out. For women, the psychology of
sexual satisfaction turns out to be much more sophisticated than most
(male) scientists have been willing to concede. Of course.
Ever since Alfred Kinsey and Masters and Johnson made the subject
of human sexual response safe for respectable scientists, laboratory
studies of the physiologic "hows" of sexual arousal have flourished.
Volunteers have been prodded, filmed, tape-recorded, interviewed,
measured, wired, and monitored, quantifying for the annals of science the
shortened breath, arched backs and feet, grimacing faces, marginally
intentional vocalizations, and jumping blood pressure of human
orgasm.
While physiological details abound, fewer scientists have attempted
to answer the "why" questions about human orgasm. To those who view human
behavior in an evolutionary framework, which we believe adds an
invaluable perspective, male orgasm is no great mystery. It's little more
than a physiologically simple ejaculation that is accompanied by a nearly
addictive incentive to seek out further sexual encounters. The greater
the number of inseminations a male achieves, the better his chances of
being genetically represented in future generations.
Compared with the more frequent and easily achieved orgasm men
experience, women's sexual climax has remained a mystery. After all,
women do not need to experience orgasm in order to conceive. So what is
the function of orgasm in females?
Darwinian theorists who made early attempts to address female
orgasm proposed that orgasm keeps a woman lying down after sex, passively
retaining sperm and increasing her probability of conception. Others
suggested that it evolved to create a stronger pair bond between lovers,
inspiring in women feelings of intimacy and trust toward mates. Some
reasoned that orgasm communicates a woman's sexual satisfaction and
devotion to a lover.
Most recently, evolutionary psychologists have been exploring the
proposition that female orgasm is a sophisticated adaptation that allows
women to manipulate--even without their own awareness--which of their
lovers will be allowed to fertilize their eggs.
Male Nipples?
The diversity of evolutionary hypotheses reflects one general
attitude: that the quickened breath, moaning, racing heart, muscular
contraction and spasms, and nearly hallucinatory states of pleasure that
orgasm inspires constitute a complex physiologic event with apparently
functional design. But critics of adaptationist hypotheses have long
argued that evolution is more slipshod than purposeful. A few, including
Harvard evolutionist Stephen lay Gould, have insisted that female orgasm
probably doesn't have a function.
Instead, Gould argues, female orgasm is incidental, caused by an
anatomical peculiarity of embryonic development. In embryos, the
undifferentiated organ that later becomes the penis in males becomes the
ditoris in females. Antiadaptationists like Gould--whose thinking
uncannily parallels Freud's belief that women spend their life in penis
envy--hold that the clitoris is, biologically speaking, an underdeveloped
penis; it can let women mimic male orgasm, but it has no functional
relevance or evolutionary history of its own.
Well known for his emphasis on chance events and structural
constraints as major players in the evolutionary process, Gould sees the
supposed functionlessness of female orgasm as a classic illustration why
scientists ought not automatically assume that a trait has adaptive
significance. He criticizes other evolutionists for overemphasizing
natural selection and functionality, and concludes that female orgasm is
like the male nipple--nothing more than developmental baggage.
Many evolutionists have rejected Gould's notion that women's
orgasms are developmentally contingent on men's. Unlike a male nipple,
adaptationists have pointed out, the female orgasm does something. It
inspires strong emotions that can affect bonding and sexual preferences,
making women more likely to prefer the company of one mate over
another.
Only during the past few years have studies begun to yield evidence
that may resolve the baggage-versus-adaptation debate over women's
orgasms.
Sperm Competition, with Women Judging
Clues for a reasonable adaptation hypothesis were readily available
by the late 1960s, when The British Medical Journal published an exchange
of letters about the muscular contractions and uterine suction associated
with women's orgasm. In one letter, a doctor reported that a patient's
uterine and vaginal contractions during sex with a sailor had pulled off
his condom. Upon inspection, the condom was found in her cervical canal!
The doctor concluded that female orgasms pull sperm closer to the egg as
well.
Yet, it was only three years ago that two British biologists, Robin
Baker and Mark Bellis, tested the so-called upsuck hypothesis. They were
building upon ideas articulated by evolutionary biologist Robert Smith,
who suggested that since women don't have orgasms every time out, female
orgasm favors some sperm over others. Baker and Bellis sought to learn
just how female orgasms might affect which of a lover's sperm is used to
fertilize a woman's eggs.
