Men and Women FAQ
The Evolution of the Sexes

Martin Sewell <martin@martinsewell.com>

last updated 13 August 2010


Evolution of Men and Women (new PDF article)

Is this article about gender or sex?

Sex. The notion that gender (which is socially constructed) is distinct from sex (which is biological) in any significant way is politically-inspired nonsense. Read on to find out why.

What is the meaning of life?

Life has no meaning, our lives are insignificant. However, we have evolved in such a way that reproduction is the sole goal for which human beings were ‘designed’ and everything else is a means to that end.

How can we have selfish genes?

Assume that there are ‘things’ that are passed on from parents to child, the minimal ‘thing’ must be the unit of inheritance. Every organism is the product of its parents, which in turn are the products of their parents, and so on. Therefore every single member of the entire lineage of every organism reproduced. This creates a massive bias in the ‘unit of inheritance’ towards motivating the individual carrying the ‘unit of inheritance’ into reaching the age of reproduction and successful reproduction, which is equivalent to saying that the ‘unit of inheritance’ is hugely biased towards survival and propagating itself. The ‘unit of inheritance’ is the gene, and the ‘selfish gene’ is a great metaphor, it couldn’t possibly be any other way.

Isn’t culture better understood in terms of memes?

No. Those who subscribe to the concept of memetics do so in an attempt to explain the evolution of culture. Culture is merely the codification of our evolved social psychology, so there is invariably a biologically-rooted explanation. It is therefore unnecessary to offer an explanation at a higher level. Memes are the answer to a question that was never asked, yet fail to explain their very own existence.

How did our minds evolve?

Evolutionary psychology proposes that human psychology can be better understood in the light of evolution. Homo sapiens originated about 200,000 years ago, and natural selection is a slow process, so human beings today are better equipped to solve the problems faced by our ancestors. The environment to which a species is adapted is known as the environment of evolutionary adaptedness (the EEA) which, for modern man, is the Pleistocene (which lasted from 1.8 million to 12,000 years before the present) where we lived in hunter-gatherer tribes on the African savannah. Evolution is survivorship bias, so our minds have adapted to surviving—by propagating our genes—in an environment that dealt with predators, food acquisition, interpersonal aggression, diseases, mate choice, child rearing, etc. For example, we are more afraid of snakes and spiders than cars, despite the fact that cars cause more deaths and injuries than creatures in developed countries.

Why reproduce sexually?

It is a mystery why sex evolved at all. The alternative to sexual reproduction is asexual reproduction, where the whole population is capable of bearing young. So the question really is, what is the point of men? Sexual reproduction has two main disadvantages: firstly, sexual species grow more slowly than asexual species, and secondly, males and females must search for each other in order to mate. The most popular hypothesis for the evolution of sex, the Red Queen theory, is that sex developed as a means of keeping one step ahead of parasites. For an informative yet readable popular science explanation, see Ridley (1993).

Why are there two sexes?

Imagine a population of hermaphrodites. Some will be genetically biased towards putting more time and effort into mating and their genes will thrive as they inseminate many others. Others will be biased towards expending energy by producing eggs and bearing babies, they will also be genetically successful as can do their best to ensure their children survive. Those individuals who lie in the middle, and specialise in neither activity, will die out. The first type leads to a small active gamete, the second a larger, static gamete. The union of two unequal gametes in reproduction is known as anisogamy. Intrasex competition ensures that this dichotomy persists. See Parker, Baker and Smith (1972).

What is special about human beings?

The following traits are either unique to humans or rare within the animal kingdom. So the puzzle, ‘why did this trait evolve?’ could perhaps be better framed as ‘why did this trait generally not evolve’. Either way, each trait, in isolation, should not be considered inevitable, but perhaps some insight can be gleamed from the combination.

Are men and women born equal?

No; things that are different are not equal. In all species, the relative investment that is made by the male and the female in their offspring determines the degree of discrimination exercised by the individual in selecting a partner. In humans, like many mammals and most animals, females can be expected to be the more discriminating in their choice of mates. Therefore females limit the reproductive success of males and men compete with other men for access to women. Women are the privileged sex (the ‘genetic celebrity’), whilst men are relatively expendable. The distribution of men’s mate value has a greater variance and more of a positive skew than the corresponding distribution for women. According to Moxon (2008), men have evolved to act as a ‘filter’ for genetic material. By stretching them out in a dominance hierarchy, genetic material that enhances the lineage is retained, whilst deleterious genetic material is eliminated from the lineage. Farrell (1986)

How different are men and women?

Are men and women surprisingly similar, or surprisingly different? The question is ill-posed, because the answer is: relative to what? Evolution has a bias towards similarity in general. For example, male and female genitals. Another example is that men have nipples because it’s not worth the evolutionary ‘bother’ of preventing its expression in the sex opposite to where it is useful. What is radically different between men and women is their motivation (see Moxon (2008)). Men must work hard, compete and take risks throughout their lives if they want any life at all, whilst women need only to look youthful and behave selfishly. A woman’s mate value is largely heritable, whilst a man’s is dependent upon the environment to a greater degree.

The figure below is from Hines (2003) and shows the magnitudes of some well-known sex differences in human behaviour compared to the magnitude of the sex difference in height.
The magnitudes of some sex differences.

Aren’t we all just individuals?

Yes, our genes ensure that we are. However, there is such a thing as universal human nature. Going further, men and women do not differ in degree but differ in kind, allowing us to generalise about men, and generalise about women. Science is all about generalizing.

What motivates humans?

Our ultimate motivation is to reproduce, but evolution requires only that we are aware of our proximate motivations, which, in order of priority, are 1) sex, 2) intra-sexual competition, and 3) survival.

What motivates men and what motivates women?

Men want (in order of priority):

  1. sex with many new short-term partners, with the hope that other men will support their bastards
  2. exclusive sexual access to a long-term partner

Women want (in order of priority):

  1. a provider husband who will invest food and care in her children
  2. a high status lover who can give those children first-class genes

Note that in the case of men, the only way a man can achieve 1 is to attain status via his rank in the dominance hierarchy, whilst 2 allows a compromise between status and reliability. Wealth is a proxy for both. Note that in the case of women, 1 and 2 can be the same man, but she is only likely to achieve this if she is highly desirable. In summary, men and women both want short-term and long-term partners, but the priorities are the opposite way around. As the more discriminating sex it is women who choose, and therefore the men who must develop a strategy. The women’s priorities dictate the probability of the strategy working, whilst the man’s preferences determine the payoff. For men, 1 is a high risk/high return strategy, whilst 2 is a lower risk/lower return strategy.

Can we overrule our genes?

No, although suggestions to the contrary are widespread. Even the great Dawkins, Dennett and Pinker claim that one can transcend one’s genes, and I suspect that they’ve bowed to political correctness in their books on this point. Moxon (2008) gets this right. The only thing that could overrule our genes is our genes themselves. The more complex, advanced and intelligent a species is, the better equipped it is at utilising its environment to accomplish the proximate goals directed by the motivational set that their genes have provided them with. It is no coincidence that suicide bombers are most prevalent among religions that prevent the largest number of males from having access to sex.

Are genes really that important?

Yes. For example, stepchildren are sixty-five times more likely to die than children living with their true parents (Daly and Wilson 1988).

Could there be cultural explanations for the differences between men and women?

Human nature is a product of culture, but culture is also a product of human nature, and both are the products of evolution. All culture is the codification of social psychology: culture only amplifies innate preferences, it doesn't manufacture them out of thin air. Behaviour depends on two thing: the environment and your genes, and your environment consists mostly of other people’s genes. This is inevitable, as we live in a largely deterministic universe.

Does race matter?

Yes. Orientals are the least sexually active and least fertile, blacks the most sexually active and most fertile, and whites are intermediate (see Rushton (2000)). For an overview of race difference in general, see Sewell (2007c), and for a theory of interracial dating, see Sewell (2007a).

What are the main differences between men and women and what effects do these differences have?

The fundamental difference between the sexes is that women give birth to their offspring, whilst men can not. Men and women do not differ in degree but differ in kind.

Why do some career women remain single?

A minority of women (about 14%) have culturally bought the notion that climbing a hierarchy is the path in life for everyone. They expend their energy in climbing work organizations so as to more consistently place themselves in the path of high status men, in doing so, they may set their criteria so very high that they remain single. The availability of eligible men decreases, and to make matters worse, the woman’s very position in a work hierarchy counts against high status men taking an interest in her because given her access to other high status men, she will be perceived by men as liable to indulge in extra-pair sex, and therefore to be an inappropriate long-term partner. Cuckoldry being man’s greatest fear. Also, by the time they reach the higher echelons of the career ladder they have lost their youth and are losing their attractiveness. For these reasons women ‘high flyers’ have poor prospects of forming long-term pair bonds.

Why do some women not want children?

Some women expend their energy in climbing work organizations so as to more consistently place themselves in the path of high status men. They set their criteria so very high for choosing a mate, it may well be that they end up not choosing anyone until the very twilight of their reproductive years, too late to have children.

Why are some people gay?

Sexual orientation is probably between 30% and 50% heritable, and although homosexuality is maladaptive for the individual, it could be beneficial for the lineage if, for example, the individual helped close relatives. Or the ‘gay gene’ could enhance fertility when found in women. No one really knows for sure.

Are we monogamous or polygynous?

Women are naturally almost monogamous whilst men are naturally almost polygynous. The majority of societies are nearly but not quite monogamous. If males can accumulate enough wealth they will practice opportunistic polygyny, either serially or simultaneously, although polygymy is largely outlawed in the West.

What do men look for in women?

Men seek youth and beauty in a mate. Youth implies that she is less likely to be attached to another man, and that she has her entire fertile period ahead of her. They seek a non-pregnant, yet fertile and healthy women; and slimness around the waist indicates not pregnant, whilst an hourglass figure signals health and fertility. Large breasts may have been an adaptation to differentiate women from girls. It could also be that men (and women) are attracted to more-exagerated-than-average physical features (and traits) that are distinct to the opposite sex. Men don’t want their sperm to be in competition with other men, nor do they want a wife who may be unfaithful, so would be put off by women who make themselves available for sex too easily. On dating sites, men advertising for women tend to place an overwhelming emphasis on cues of physical attractiveness in prospective partners.

What do women look for in men?

Women wish to attract high status men (plus reliability for long-term partners) and to achieve this they simply need to appear youthful, look attractive and behave selfishly. Women list significantly more traits in their demands; and place a strong emphasis on cues related to wealth and status. Women may also seek potential status in a man. If a man wishes to attain a mate of higher value than his status would normally allow, he first has to deceive a woman about his reliability in the future (and to do this effectively he has to deceive himself) and then maintain the illusion by actually hanging around in the early years of his children’s lives. Women simply do not understand that really what they are experiencing when they select a man to fall in love with, is that they are not so much ‘falling in love’ as ‘falling in respect’. They don’t seem to grasp that it is the various facets of male status that are their selecting criteria, and instead imagine that it is something to do with a chance stumbling on a Mr Right in terms of a constellation of personality factors with which they mysteriously gel (plus the ‘tall dark and handsome’ thing). You’ve seen the films when a man and a woman literally bump into each other in a corridor and one of them drops some books and the other helps to pick them up. And then they fall in love. It may not be reality, but it is a stylization of a dream romance (according to the woman). Women speak of certain men being ‘good in bed’, when in fact they are nothing of the sort, they are simply perceived as being of high status. The tragedy that the world is run by rich, arrogant, war-mongering and frequently good looking men (rather than those best equipped to do the job) is because women select for these characteristics. They spend their lives attempting to place themselves in the path of high status men, then complain when their high status partner (such as a trader in the city) doesn’t have time for them. Men who show consideration and give their time are implying that they need to do so, so are effectively signalling their low status. Ironically, despite being in complete control of the (largely predictable) dating game, women often have a poor grasp of what is actually going on.

What is romantic love?

There are three stages to falling in love (BBC 2004):

  1. Lust is driven by the sex hormones testosterone and oestrogen.
  2. Attraction is the truly love-struck phase and the following ‘monoamines’ play an important role: dopamine, norepinephrine and serotonin.
  3. Attachment is the longest lasting phase and two hormones are released by the nervous system, oxytocin and vasopressin.

Feelings of romantic love are instrumental to sex with a long-term partner. Although the phenomenon is neither a particularly common, nor a strictly necessary, means of achieving this goal.

Why does a man fall in love with a woman?
Romantic love is one way that a man can convince a prospective or present partner of their reliability (women seek status plus reliability in long-term partners). So romantic love is an instrument of sex and is a result of the evolutionary process that makes men stay around to help raise children. It is both a deception and a self-deception (the latter necessary to convincingly achieve the former). The intensity of the feelings of love invariably falls off, whereas the power of the motivation of sex with a variety of partners never diminishes.

Why does a woman fall in love with a man?
Romantic love is the way a woman convinces herself that it is worth the risk of banking on the reliability of her male partner. It’s another self- and mutual deception instrumental to sex.

What is marriage?

Marriage is the name we give to the formalization of the human long-term pair bond, which is quite natural and exists in all societies past and present. It evolved primarily to satisfy the female need for a reliable partner, and does so by ensuring provisioning by the man. For marriage to be so popular, there must be something in it for the men too, and there is. Regardless of his culture’s specific wedding vows, the groom makes an explicit contract enforceable by the whole social group to provision a woman and any resulting children in exchange for exclusive sexual access so as to guarantee paternity of any children. The wife is absolved of all responsibility for provisioning so that she can focus on home-making and child-rearing. This is economics, the division of labour. Married men still desire extra-pair sex and (to a lesser extent) women may be tempted to have extra-pair sex with a man of higher status than her husband.

How do men and women get on at work?

Why are there more men in higher office and the sciences?

Why do women (sometimes) have orgasms?

Women are more likely to have an orgasm when they are having an affair (which would be with a male of higher status than her long-term partner). This both encourages women psychologically to indulge in extra-pair sex and aids conception mechanically. If the woman can pass off the child as the long-term partner’s, she can get the best of both worlds for her offspring: better genes than that of the male provisioner whilst retaining the reliable provisioning by the long-term mate. A surprising number of women experience orgasm whilst being raped (Levin and van Berlo 2004) (for a possible explanation, see below).

Why do some people have rape fantasies?

Rape fantasies occur to about 24% of men and 36% of women (Knox 1984, p. 283). Over 10% of women report that being forced to have sex is their favourite sexual fantasy (Doskoch 1995). Moxon (2008) posits that women’s rape fantasies could be innate. The environment to which a species is adapted is known as the environment of evolutionary adaptedness (the EEA) which, for modern man, is the Pleistocene (which lasted from 1.8 million to 12,000 years before the present) where we lived in hunter-gatherer tribes on the African savannah. During the EEA the size of social groups was likely to have been constrained by the information-processing capacities of the brain, with 150 people being a good average. Because we lived in small groups, ‘policing’ ensured no opportunity for adultery or rape (not without serious retribution). The opportunity came with raiding neighbouring communities. Successful raiders, and especially the leaders of a successful raiding party, were likely to be males of high fitness and high status within their own community. For most women in the raided community who may be the subject of ‘forced’ sex, their ‘attackers’ would be of higher status than their own long-term partners. For this reason it would have been in the interests, evolutionarily speaking, of women in raided communities to succumb to sex with raiders. This may also explain why a surprising number of women experience a ‘deer in headlights’ reaction and a have a surprisingly high probability of orgasm (see above) whilst being raped, plus the extraordinary high rate (estimated at over 50%) of fabricated rape allegations. In any case, female sexual responsiveness is enhanced by the sense of being overpowered (Eibl-Eibesfeldt 1990). In contrast to the EEA, in modern times stranger rapists tend to be men of low mate value.

Why do women have concealed ovulation?

Concealed ovulation is advantageous to women because it makes both adultery and fidelity easier. Ovulation is less concealed from the woman (or her unconscious) than the man, so the woman knows the optimal time to have an extramarital liaison without deserting her husband.

Why is it worse for a woman to commit adultery than a man?

Cuckoldry is an asymmetrical fate. A woman loses no genetic investment if her husband is unfaithful, but a man risks unwittingly raising a bastard. So it is not a ‘double standard’ at all: a man having extra-pair sex is in no way threatening his pair bond, but a woman so doing very clearly is.

Do parents prefer boys or girls?

Those of high social status prefer sons, whilst those of low social status prefer daughters (Trivers and Willard). The preference for boys in parts of Asia fits this principle if one takes into account the fact that people tend to be overly optimistic and overconfident—especially men (Barber and Odean 2001) and Asians (excluding Japanese) (Wright et al., 1978; Wright and Phillips, 1980; Wright and Wisudha, 1982; Wright et al., 1983; Yates et al., 1989; Lee et al., 1995; Whitcomb et al., 1995; Yates et al., 1997, 1998; Chuang and Wang, 2005).

Is it reasonable for women, in general, to moan about men (in general), or vice versa?

No, because each sex shapes the other. For example, men have an aggressive nature because women have preferred them that way (or have allowed aggressive men to defeat other men in contests over women—it amounts to the same thing). Likewise, women have hourglass-shaped bodies because men have preferred them that way.

Why are women bitchy?

There is only a small minority of men of high enough status that top clique women go for, so there is much mileage in these women denigrating other women in the top clique in the eyes of men by ascribing to them sexual impropriety. This is the ‘indirect’ or ‘relational’ aggression women are famous for. The surest way to put off men from forming long-term sexual partnership is the prospect of infidelity. This is why the biggest put-downs in the school playground and beyond are girls accusing other girls of being ‘slags’, and various insults amounting to the same thing.

What are the political implications of the differences between men and women?

As a natural consequence of evolution women and high status men ensure that all societies are set up with a primary goal of preventing the majority of males from expressing their sexuality in anything but a minimal way. That is, the primary goal of society is to suppress the primary goal of the majority of men. The upshot of this is clear: the most disadvantaged in society are low status men (and even high-status men are forced to compete and take risks to attain that status). Feminism is the advocacy of women’s rights on the ground of the equality of the sexes. Firstly, given that men and women do not differ in degree but differ in kind, the fundamental assumption that feminism rests upon (equality of the sexes) is profoundly wrong. Secondly, and worst still, the sex that feminism seeks to protect and promote is the already privileged; feminism is worse than being merely unscientific, it is anti-scientific. For more on feminism, see Sewell (2007b).

Where can I find out more?

Farrell (1986, 1993) famously explained life from a man’s perspective and exposed the myth of male power, Ridley (1993) provides great insight into evolution, sex, men and women, Hakim (2004) is the authority on women and work, whilst Moxon (2008) is based on science from the ground up and is the most radical, thorough and accurate portrayal of the relationships between men and women in general.


cheater detection
In order for cooperation to have stabilized humans have evolved cognitive mechanisms that allowed them to detect deception related to cheating in resource exchange and mate selection criteria. See Cosmides (1989).
dominance hierarchy
A form of animal social structure that exists when a group of individuals belonging to the same species share a territory and a ranking exists, with each animal dominant over those below it and submissive to those above it. Dominance-submission signalling goes on between the animals. Dominance hierarchies occur in most social animal species, such as primates, wolves and birds, notably chickens (‘pecking order’). In human beings, men exist in a dominance hierarchy. A man’s rank in the dominance hierarchy will be correlated with height, muscularity, symmetry, attractiveness, intelligence, income and willingness to take risks.
A group of people in which all members feel a strong sense of identity with the group, foster a sense of elitism about the group and tend to act so as to exclude others (the out-group).
intra-sexual ‘policing’
Men police other men to ensure that there is no forced sex. Women tend to object to other women who are seen as ‘letting the side down’ in making available or intimating the availability of sex without a commitment price.
A group comprised of all people who do not belong to a specific in-group.
proximate cause
A level of explanation. In behavioural terms the immediate mechanism or stimulus that initiates or triggers a pattern of behaviour.
Self-deception is the process of misleading ourselves to accept as true or valid that which is false or invalid.
Status is equivalent to ‘rank’ in the male dominance hierarchy.
ultimate cause
A level of explanation. The explanation for the behaviour of an organism that reveals its adaptive value, it explains why the behaviour increases its ability to survive and reproduce.