Female gene shopping
Shouldn’t we assume that every normal man of average build and good health would also be equipped with a sufficiently large and fully functional penis?
Well, I do believe that there is sound biological logic as to why we shouldn’t be so sure about this. Humans obviously have a biological character and a cultural character. Our cultural character accounts for much of our conscious behavior. On the other hand, our emotions and unconscious states of mind (including desires) are largely an affair of our biological character.
Our cultural character has changed tremendously over the last 2,000 to 3,000 years, but our biological character is still basically the same as it was for our Stone Age ancestors some 10,000 years ago, or their predecessors some 50,000 years ago.
And there is no doubt that in earlier phases of our history, our sexual function and behavior were largely a matter of mammalian biology.
A salient aspect of mammalian sexuality is what Darwin defined as male competition and female choice. Mammalian males typically strive to inseminate as many females of the species as they can handle. Females display a profound preference for males with what they (unconsciously, in accordance with their biological character) consider the best genes.
But this is not yet the full story. Human females, as they developed throughout the past 6 million years, have more differentiated interests than just mating with the male with the best genes. Human females have a material interest in male-female bonding. In order to preserve their genes, human females spend many years raising their young. And unlike other mammalian species, human females had and have to take care of offspring born years apart, and possibly of different fathers. (Great apes have a slower reproductive rate, as females only give birth every few years, after having raised the offspring born previously.)
Human and pre-human females, during millions of years of evolution, developed a survival strategy that includes the permanent binding of a male partner. The benefit for the male partner lay, and lies, in the permanent availability of a female for sexual intercourse.
So far, this is standard anthropology.
But there is a twist, which is the definite interest of both the male and the female partner in being unfaithful.
For the male, the strategic benefit of unfaithfulness is obvious. Getting a shot at another female means an increased chance to preserve one’s genes. Spreading one’s genes in acts of unfaithfulness, furthermore, is a low-risk behavior for men. There is potentially no additional obligation. The female is inseminated, and after that, she alone cares for the common pool of genes, or she enlists the help of another man who happens to be that female’s permanent partner.
For the female, the benefit of unfaithfulness is subtler. In a human or hominin society where one-on-one bonding is the standard pattern, only a few women end up with the most genetically fit males, while other females form permanent partnerships with average males who nevertheless can be of valuable help in raising offspring.
However, the biological interest of these females is still to mix their own genes not with the genes of average males, but with those of the fittest men.
The solution is female unfaithfulness: have occasional, even secretive, intercourse with a genetically fit male, and after being inseminated, take any male you can get as a permanent partner to help in raising one’s offspring!
This is, of course, a complex pattern of biological sexual behavior. It’s never a clear-cut scheme. Rather, the pattern is one of a trend. Because the female can bind an average male only by giving him sexual access, and by allowing him at least the illusion that all the offspring in the liaison are his, it will have occurred on a regular basis that indeed, a female human gave birth to the offspring of average males. A standard setting may have been that some of the offspring resulted from unfaithfulness with genetically fit males, and others from a permanent relationship with a long-term partner.
The whole thing developed like a kind of involuntary horse-trading.
Much also depended on the economics of the times. When economic basics allowed more complex societies to develop, dominant males were capable of maintaining a larger pool of females who were not bonding at all with average males. This is evident in the harem-building of the high-status males of all early complex human societies. But harem-building is an aspect primarily of male sexuality in situations where one man has at his disposal the means to exclude other males from a pool of females. Harem-building is also an aspect of male dominance.
On the part of the females, living in a harem is probably much less in congruence with their biological interests as they cannot follow the trait of their biological character, which would be to monopolize a man.
Biological sexual behavior is obviously regulated through sexual desires.
Again, for men, this is rather straightforward. Because the most promising sexual strategy for men is to spread their genes, and sperm, throughout as many females as possible, the behavioral sexual goal of men is to either possess exclusively as many females as possible, or to inseminate not only the one or few females he directly possesses but also, in acts of unfaithfulness, as many females as possible who are in permanent bonds with other males.
Therefore, male sexual strategy is definitely directed at a multitude of females. And as the regulatory force is desire, it is no surprise that there is a clear incentive to add new partners: sex with new partners typically is more exciting (known as the Coolidge effect), so there is a higher likelihood of orgasm and ejaculation.
For the female, the most promising sexual strategy is to first play it safe: have one sexual partner in a permanent relationship who can provide material help in raising the offspring he considers his own. However, beyond this, a success-driven female strategy includes seeking better, or the best, genes to pair with through regular acts of unfaithfulness with genetically fit males.
For such a setting, female sexual desires have to be more differentiated than those of men. Nature regulates this by not allowing them full sexual satisfaction with the average male who may be their permanent partner. They may bond well with an average male, and develop the emotions summarized as “love”, but there is an element that becomes obvious to them only over time, and usually only after having given birth to an offspring fathered by a long-term partner (thus already making sure of her genes’ survival in principle). This element is her desire for sexual satisfaction with a male who displays superior genetic fitness indicators. Thus, female sexual desire, more than male sexual desire, is dualistic: have a love relationship with a permanent partner, and seek sexual satisfaction with a genetically fit male.
If biological science teaches us anything, it is this: nothing is accidental. Every phenomenon we encounter in the world of living species has developed through evolution and natural selection in precisely the fashion we encounter it because this is what has proven to be the best survival strategy.
For this reason, we have to make sense of the following: almost all men easily achieve orgasm and ejaculation through sexual intercourse. However, the majority of women do not consistently achieve orgasm through penile-vaginal penetration alone, regardless of penis size, as female sexual satisfaction is primarily driven by clitoral stimulation. Evolutionary hypotheses regarding female extra-pair copulation do not focus on penis size causing vaginal orgasms, but rather suggest that women may seek out sexual relationships with genetically fit males (those displaying traits like facial symmetry, behavioral dominance, or immunocompatibility) to secure better genetic material for their offspring, even while bonded to a long-term partner who provides resources.
Based on these anthropological considerations, male sexual anxiety regarding physical endowment is a well-documented phenomenon. However, from a biological standpoint, penis size is not the primary driver of female sexual satisfaction or orgasm. Evolutionary theories of female infidelity suggest that women seeking extra-pair copulations are driven by indicators of genetic fitness (such as physical symmetry or dominant behavior) rather than anatomical measurements. Therefore, a man’s ability to retain a long-term partner relies heavily on his role as a provider and companion, while the risk of female infidelity is tied to her pursuit of genetic diversity or superior genetic traits, rather than purely physical endowment.