Chapter 26: A sly rabbit has three burrows – Part 3

Now that it has been established that physical and social qualities play a major role when women are contemplating short-term sexual relationships or infidelity,[1] the next question concerns what exactly they regard as attractive and therefore as genetically superior. As pointed out in the chapters about the definition of beauty[2] and importance of smell in mate selection,[3] body symmetry is one of the key traits in the assessment of a person’s sex appeal. The same remains true for the choice of extra-pair sexual partners. Since symmetry is supposed to be a heritable marker of fitness by signalling resistance to pathogens and environmental stress, this feature represents a fundamental indicator for the quality and health status of people. Furthermore, it is said that symmetrical men also tend to be larger in size, more muscular and vigorous than their less symmetrical peers.[4] Accordingly, it only seems reasonable that women would prefer such fellows for their carnal affairs – one of the central findings in Gangestad and Thornhill’s version of the Sweaty T-shirt Experi­ment.[5] Yet this is not even the most surprising aspect in adulterous sex selection. What may shock us is to know that women loosen their quality standards significantly when seeking brief encoun­ters. For instance, while they expect their husbands to be in the 61st percentile in terms of degree of education, the 47th percentile is enough for the fling. In line with the sexy son hypothesis, they reciprocally require their one-night stands to be in the 76th per­centile on sexiness (77th on physical attractiveness), but set the bar much lower for their hus­bands, with the 58th percentile (on sexiness), respectively the 54th percentile (on phy­sical attrac­tiveness).[6]

These results show one thing: Namely that men do not hold a monopoly on sexual objectifi­cation. For good reasons, women complain about men’s obsession with ladies’ phy­sical appea­­rance and sexual availability.[7] They feel treated as sexual objects, their bodies being much more important than their personalities or other capabilities, such as intellect, kind­ness, humour, etc. The sexy son hypothesis suggests that some females are not so differ­ent from those superficial machos, caring just as much about appearance and sexual grati­fi­cation. In their minds, lads only come in two categories: The hubs and the studs. This form of discrimination is evocative of the so-called Madonna-whore complex, which was descri­bed as a bias to see women as either saintlike virgins or impure pros­titutes.[8] Trans­posing this dichotomy to the female context, I would like to use the term “Casanova-hubby complex” to designate that same prejudice, i.e., when a woman regards men as either hus­bands (sought after for their resources) or lovers (sought after for their genes), but not both.

The previous paragraph sounds derogative towards all those females who opt for a two-timing strategy. Criticism is not the intent though. On the contrary, it should be good news to know that men and women are much more similar than one would think. Furthermore, promiscuous behaviour does not have to be morally reprehensible. Thinking about it, no harm is done if the couple is not married or does not plan on having children. In that case, if the cheated partner feels offended, it is more a question of jealousy (i.e., his problem) than of ethics. So what hurts the most is not always the fact that a loved one had intercourse with another man (or woman), but the storytelling that follows when the culprit is trying to erase the traces of her “misdemeanour”. No one likes to be taken for a ride. In this regard, lying and deception are much more reprehensible than sexual frivolity.

If one lesson has to be learned from this chapter, it is that Darwin’s “coy female” is no more than an anachronistic male fantasy.[9] Some ladies enjoy casual sex, sleeping with several handsome men – sometimes subsequently, sometimes simultaneously. Unconsciously, they do so because they wish to become pregnant with a genetically superior child, thus gaining a reproductive advantage. Nothing more natural than that. Thus, it is not only all right to be a slut, it is actually highly recommended to have casual sex. If not for herself, then at least for her baby. A woman does what she must – in spite of personal consequences, in spite of obstacles and dangers, and pressures – and that is the basis of all human posterity.


Related proverbs and citations:


zhǎo gè ài wǒ de zuò lǎo gong, zhǎo gè wǒ ài de zuò qíng rén

A verse suggesting a woman marry the man who loves her, and to make the man she loves her lover.



[1]    Campbell (2002), p. 175

[2]    See chapter 15 “Flowers look different through different eyes”.

[3]    See chapter 16 “When you have musk, you will automatically have fragrance”.

[4]    Buss (2003), p. 236

[5]    Cited in: Buss (2003), pp. 236-237

[6]    Cited in: Buss (2000), pp. 163-164

[7]    Buss (2000), p. 163

[8]    See chapter 1 “Men are like mud, women are like water”.

[9]    Ryan / Jetha (2010), p. 266

Chapter 26: A sly rabbit has three burrows – Part 2

The notion of human sperm competition provides another reason why promiscuity makes sense from a reproductive standpoint. Defined as the “competition between sperm of two or more males for the fertilisation of an ova”[1], sperm competition results from the choice of a woman to have sex with several men. The “sperm war”[2] she sets in motion helps her ensure that the most successful sperm cell will prevail and that she will conceive a baby with the contestant with the strongest army (made of millions of eager spermatozoa) fighting on his behalf.[3] Since human seed can stay alive within the woman’s reproductive system for up to a week, the race can easily take several days. So if she has unprotected sex with more than one man within that time frame, she sets the stage for a battle of their gametes.[4] The victor (there can be only one) gets to fertilise her egg (the Prize), thus initiating her maternity (the Quickening). Given that the winner has to beat not only the spermatozoa of its own kind but also those of one or more external rivals, the genetic material it carries must be of supreme quality. In line with the slogan “competition is good for business”, a promiscuous woman does nothing else than creating more choice for her valuable ovum, thereby improving the chances to produce more viable offspring. In this context, notice that the concept of “sperm competition” is different from the “sperm retention” theory, which states that women have more “high sperm retention” orgasms with their affair partners than with their primary mate (as measured by the amount of semen churned out immediately after inter­course).[5] In addition, it appears that unfaithful women tend to time their sexual escapades with their lovers (that is, their orgasms) around ovulation, i.e., at that point of their menstrual cycle when they are the most fecund.[6] Whether or not the decision is deli­berate, these findings show that the wish for procreation can play an important role in adul­tery, and may also explain why ladies place particular importance on sexual gratification when electing their paramour.[7]

As previously observed, women are essentially attracted to men who can provide two types of benefits: Plenty of resources and good genes. Alas, one single man is not always able to fulfil both requirements at the same time, which are often regarded as contradictory (think about the hard working nerd who neglects his personal appearance, or about the beefcake who prefers to spend his time in the gym rather than studying). Even if such a prospective mate does exist, he could be a philanderer or a “bad boy” himself,[8] not willing to commit to the woman in question. Worse still, he might be so popular that he ignores her, or is not interested in her at all. In such a situation, she faces a classical Dads vs. Cads[9] trade-off: Should she try to get an average-looking, but responsible provider husband who will offer her food, shelter, care, and invest in her progeny? Although he is likely to be a good father and a loyal partner, it is possible that he will score lower on the “health” or “gene quality” scale. Or is she better off with the handsome, masculine-looking hunk that will pass his first-class genes to her babies? The risk here is that he could channel some of his assets and sexual energy toward other females and their children. One way to deal with this dilemma is by opting for a so-called dual mating strategy and try to enjoy the best of both worlds.[10] Under this scheme, a woman simply hooks up with several men: One who delivers the vital resources and with whom she is in an (officially) monogamous relation­ship; and a few other ones on the side who are in charge of impregnating her with healthy, fit and robust off­spring, while at the same time delighting her with orgasmic pleasures. By spreading her luck between various mates, she not only garners genes from someone she considers as geneti­cally superior but also makes sure that her successors will be safe, have enough to eat, as well as have a good education.[11] Such a plan can only work out if her cuckold husband does not find out, in which case he could withhold his support and even banish her and her bastards. In other words, the dual strategy always comes with a number of risks. Never­theless, if she is smart and cautious, she can probably get away with it.

Theoretical constructs such as the sexy son hypothesis[12] also support the proposition that women are by nature interested in sexual variety. Due to the relatively long gestation period of human babies, it is not as easy for females to disseminate their genes as it is for males, at least not immediately. However, they can achieve this goal indirectly, through their sons. In order to increase the viability and reproductive success of their future generations, they need to select one or more casual sex partners who can help them bear sons who themselves will have a high value on the mating market. For that purpose, what else could be more effective than a casual fling with a well-favoured bad boy?[13] According to the sexy son hypothesis, women who pick potential fathers for their genetic merits rather than their qualities as caregivers reap an evolutionary advantage.[14] While this logic runs against the assumption that women nominate partners based on their ability to gather resources and on their wil­lingness to make a long-term commit­ment,[15] let us clarify once more that what is being said here only applies to the selection of a lover (not of a husband).



[1]    Parker (1970)

[2]    Baker (1996)

[3]    Campbell (2002), p. 48

[4]    Buss (2000), pp. 171-172

[5]    See chapter 32 “Hearing something one hundred times is not as good as seeing it once”.

[6]    Ridley (1993), p. 225

[7]    Buss (2000), p. 173

[8]    See chapter 22 “Man not bad, woman won’t bed”.

[9]    Campbell (2002), p. 185

[10]  Meston / Buss (2009), p. 14

[11]  Titus / Fadal (2009), p. 64

[12]  See chapters 14 “Fair lady is what gentleman seeks” and 19 “If you plant melons, you get melons; if you plant beans, you get beans”.

[13]  Quirk (2006), p. 129

[14]  Cited in:

[15]  See chapters 17 “Finding a good job is nothing compared to finding a good husband” and 21 “You can’t lead the life of a whore and expect a chastity monument”.