Home Biological aspects of sexuality Justifying biological & evolutionary precedents

Justifying biological & evolutionary precedents

Biological precedents provide crucial evidence for human sexuality. The key precedents include:

  • The evolution of the sex organs;
  • The role of male orgasm;
  • The incidence of female orgasm in other animals; and
  • Male proactivity and female passivity.

Every embryo has a structure that eventually forms the sex organ (clitoris or penis). The clitoris is referred to as the homologue of (equivalent organ to) the penis. The clitoris cannot be a reproductive organ because it plays no role in reproduction. The vagina, on the other hand, plays a crucial role. For impregnation to occur, a man must ejaculate into the vagina. The male and female internal reproductive organs develop from different foetal anatomy. If the vagina was involved in female orgasm, this would mean that male and female responsiveness have evolved quite separately. Logically orgasm must result from similar physiological process for men and women.

A man’s key reproductive priority is to maximise his ejaculations (into a vagina) and increase his chances of procreating. Male responsiveness arises because male orgasm triggers ejaculation of sperm. Women’s top reproductive priority is to find a mate who will be dedicated to protecting and supporting her through the long process of bearing and raising a child.

While male orgasm (co-incident with ejaculation) is 100% vital to men’s reproductive capability, female orgasm has zero impact on women’s ability to conceive. Women do not have an arousal cycle as men do. It would be very strange if female responsiveness was common because female orgasm plays no part in human reproduction. This is why even responsive women orgasm sporadically and infrequently, with many days or weeks between orgasms. It is likely that female orgasm has become less common over time.

Anyone who is intent on orgasm knows what they need to do to achieve it. Humans reproduction is successful because of men’s proactivity (male sex drive) and women’s sexual passivity. Women are more willing to accept intercourse (with all its risks) as a loving-making act because it leads to family. Yet most men want intercourse considerably more frequently than is required for reproduction. Women are generally much less keen on engaging in the more explicit genital stimulation used by gays of both sexes.

We share our ancestry with all life on earth. But more recently we had ancestors in common with primates and before that mammals. If a characteristic, such as female orgasm, doesn’t exist in these two groups we need evidence to explain how women might have evolved a capability. Mammals have been around for about 225 million years. Primates appeared about 55 million years ago. There is no evidence to suggest that female mammals orgasm any time. In other mammals, masturbation is primarily associated with males. Some female mammals do masturbate but since they do not ejaculate it is difficult to establish that they ever orgasm.

In mammals, the male generally initiates the mating act. Within primates the male initiates genital stimulation both of himself as well as the opposite sex. Some female primates stimulate a male or allow a male to stimulate them genitally. But since this activity is only engaged in by some females (as for women), it is a conscious behaviour aimed at obtaining the benefit of male support rather than being a sign of universal female responsiveness.

Women are often presumed to suffer from sexual repression. It’s not clear why girls should be affected and not boys. An obvious answer is that girls are impregnated. Rather than being repression, it’s just common sense. Once reliable contraception became available it was assumed that intercourse should instantly become for women exactly what it represented for men: an opportunity to enjoy erotic pleasure, arousal and orgasm. But our emotional and sexual responses have evolved over millions of years. Girls cannot evolve a sex drive just because they have reliable contraception.

A man gives through his role as protector (where a man supports the family) and defender (where a man risks his life). Families depend on men for protection. But men are inclined to take risk. This means that men often represent the greatest threat to women and children in the first place. Most of the time men have little interest in women, so when a man notices her, a woman is complimented especially if he is successful. If a woman sees an advantage in having a man’s protection, she may be motivated to please him.

Women may flirt to indicate their amenability to a man they admire. This is a conscious behaviour and not a sign of sexual arousal. Women have learned that when they offer intercourse, men are generous in return. So women have an incentive to offer intercourse regardless of their own pleasure. If a woman depends on a man’s willingness to fight or earn, it is difficult for her to complain when he wants the intimacy he needs from sex.

Outside of the human species, orgasm is infrequent and possibly absent among females of most species of mammal. (Alfred Kinsey 1953)