4. Gender & Relationships

Why do women and men think differently. Maybe evolution has answers? On the face of it, what is the best possible outcome for a man? To sleep with as many women as possible, as any popular rap song will attest to. And what is the best possible outcome for a women? To find a man who will be there, always, irrespective as the runaway success of Twilight will incontrovertibly assert. These outcomes seem diametrically opposite. Superficially, women and men have sharply diverging aims, one’s black to the other’s white. Yes, Hawking’s mystery is losing some of its sheen.

Evolutionary Psychology

Evolutionarily, we know that we exist to reproduce. However, men can have children whenever they feel like, while women can have a child maybe once a year. Hence, the “best possible outcomes” discussed above. If you’re a women, you want your kids to count, because you only have these many chances. If you’re man, eh, it doesn’t matter. You’ve got plenty of chances.

Since women had to make their children count, they developed heightened sensibilities to danger, security and stability. Men, on the other hand, developed what helped them father more children: aggression and risk taking. For a women to see her children survive, she had to protect them till they could fend for themselves. If a woman had a child at 20, and then lost her child at the age of 15, she was now 35. Her chances of having more children are rapidly vanishing. The risk carried with losing a child is simply too high to allow complacency. This is the probably reason for the strong mothering instinct.

The forces that lead to the physical differences are difficult to tease apart, but I would guess that because women had a greater stake in their children, as discussed, and because pregnancy incapacitated them for months at a time, tasks that were more physically demanding fell to men. At this is at a time when family size was much larger, which meant the incapacitating effects of pregnancy were magnified because women were pregnant for far longer. And of course, since everything is an evolutionary arms race, which means all advantageous characteristics will be taken to the limit, and since men competed for women, those psychological characteristics self reinforced. Both men and women evolved their own evolutionary adaptations to compete with and evolve with each other. Is it right to think of men and women being in an evolutionary arms race with the aim of ‘getting’ the best possible mate? It certainly is distasteful. Because women could not compete with men on a physical basis, evolution’s random adaptational processes took them in different directions, in the direction of leveraging the human psyche. Crudely, there are two ways to gain power among humans: physical and psychological.

Evolutionary Roots: From Chimpanzees

How did this evolve? We can look to the closest related great ape, the chimpanzee. In chimpanzees, the alpha male maintains a harem, while other males constantly seek to challenge him. Now throw two rather curious and fascinating human characteristics into the mix. All humans mate in secret, and all humans carry the concept of marriage, or ‘pair-bonding’ with them. The former means the alpha male cannot be sure his harem is faithful. This breaks down the monopoly over reproduction. And over time, the female strategy of mating in secrecy forces the old monopolistic system over the brink, into the pair-bonding we know so well. Sex in secret allows females to choose less aggressive males, and switch equilibrium from dominance to pair-bonding. To buttress the point from here, I quote, “While female effective population size (the number of individuals successfully producing offspring and contributing to the gene pool) …. increased around the time of human expansion out of Africa (about 80,000–100,000 years ago), male effective population size …. did not increase until 18,000 years ago, which coincides with the advent of agriculture.”. Which translates to – humans went from the primal monopolistic system to pair bonding or marriage.

r/K Selection Theory

In marriage both parents are wholly invested in their children. The advantage is that offspring receive more care and attention. This gels with r/k selection theory in biology that species can optimize for many offspring with low care, or few offspring with high care. We tended to the latter strategy because that’s what children need for survival, and marriage ties into it. And how does marriage begin? Courtship rituals. Men select for fertility, and can size that up in a glance. Women need to select for behaviour, and that is not so simple a matter. Hence, the courtship rituals, allowing time to judge character.

We discussed that a woman wants a man who will be faithful and around to see their children survive into adulthood. Now, for her genes to be passed down, her children too need to reproduce, right? What if she has a son. For reproductive success, her son needs to exhibit characteristics that are the opposite of what she herself wanted. In other words, the characteristics she needs in her son are the exact opposite to the characteristics she desires in her husband. Does this mean women that should have the children of aggressive, risk taking men and get faithful men to raise those children? But then the number of faithful men would decrease and their value would go up. So perhaps, there’s some sort of equilibrium between aggressive and faithful men.

From Apes to Humans

At this point, you can object that notions of love and companionship contradict assertions of conflict between the sexes. If we can fall in love and marry, then obviously there are conditions under which the sex’s best outcomes meet. Why do we have monogamy then? A hypothesis in that in the alpha male system, there’s too much conflict between males. A society would be disrupted by the constant jostling between males for females. In a monogamous society, every man is guaranteed a wife. And men, no matter how powerful, are barred from having more than one wife. This eliminates the need for men to fight over mates. In this hypothesis, monogamy is a consequence of post-neolithic societies where conflict between men must be minimized. Note that “pair bonding” and “monogamy” are distinct terms. Monogamy is a result of societal evolution whereas pair-bonding has more ancient evolutionary roots. I’m not discussing “pair-bonding” here.

As humans got smarter, intelligence meant a concomitant increase in gestation period. Children are vulnerable for the several years. If children don’t have both parents around for their period of vulnerability, who ensures their survival? As we know, mothers are were already invested in their children. But this vulnerability meant that having fathers stick around increase the odds of their children surviving. Perhaps, this increased vulnerability from increased intelligence made it more beneficial for fathers to invest in their children than to have more children. That is, men move from a r strategy to a K strategy. At this point, it’s interesting to consider the social interest. Society needs its members to reproduce if it is to survive. What pressures does society apply? Society teaches us monogamy because, as discussed, monogamy is in society’s best interests. Perhaps, society also teaches us to be good, stable parents. As in, it isn’t only in our interest to help our children succeed but also in society’s interests. Thus, it’s hard to tell where individual motivation ends and societal motivation begins.

The 21st Century


Contraception means sex does not result in pregnancy. This result cannot be emphasized enough. Contraception arrived in the 1960s. With contraception, women are freed from risking pregnancy with sex. Concomitantly, men cannot pursue a r strategy because sex with multiple partners won’t result in children. Hence, men are restricted to having children through marriage. This is an additional pressure on men to commit to monogamous relationships.

Changing Ideals of Marriage: Love and Arranged Marriages

Traditionally, women “married up”. That is, they selected older men who had higher social status, power, and wealth. The reason being these men could better provide for their children. Men, on the other hand, selected for attractiveness, marrying younger women. Attractiveness is a proxy for higher fitness and better genes, and presumably, the ability to bear more and better offspring.

That changed in the 21st century where gender roles are far more equal. For a full description, see the first third of recent male mating dynamics. Suffice to say, both sexes now look for a “soulmate” instead of looking for traditional gender roles. For women, they do not need men to provide for them. For men, one might speculate that advances in medical technology mean women’s fitness is less of a factor in childbearing.

Why do some parts of the world practice arrange marriage? My hypothesis is that arranged marriages occur where the rule of law is weak. Arranged marriages are a way for both parties to ensure that the other party has a stable background and a safety net. This is essential where there is no rule of law or social safety net. Arranged marriages also serve the families of both parties in the form an alliance, providing a broader network of relationships to fall back on. Thus, economic progress is a factor in moving towards love marriages.

Other Factors

Short-term & Long-term Mating Strategies

As discussed previously, for women an optimal strategy is to have the children of an aggressive man but marry a stable man. Thus the short-term mating strategy for women is to mate with aggressive/assertive men who won’t necessarily be great long-term prospects. Their long-term strategy is to find a stable, caring husband. Similarly, for men the short-term strategy is to have multiple partners while the long-term strategy to find a stable, caring wife.

Female Neuroticism and Male Psychoticism

  • “Men were generally higher on Psychoticism than women.” Pg. 863 of [1].
  • “Marital satisfaction was higher for men higher on Psychoticism and lower on Neuroticism than women.” Pg. 866 of [1].
  • “Women are more neurotic than men.” {Forgot the source, need to look this up}
  • Assume that psychoticism in men is not selected against and neuroticism in women is not selected against. Are women really attracted to psychotic men and are men really attracted to psychotic women? I don’t know. But one could argue that neuroticism makes a women more feminine and psychoticism (as in assertiveness/ego/arrogance) makes a man more masculine. This argument provides a reason for what we sometimes observe: Women select men who are arrogant and self-centered while men select women who are neurotic.

    Why Women are Penalized for Promiscuity

    Both men and women penalize women who are viewed as promiscuous. Why?

    Because humans have sex in secret, men cannot determine the parentage of offspring with certainty. The worst possible fate for a man is to raise another man’s offspring without knowing it. Thus men penalize women who are perceived as promiscuous.

    Women penalize other promiscuous women because those women reduce the “market value” of sex. As in Aristotle’s Lysistrata, women withhold sex from men until a peace treaty is signed. In other words, there’s a “social contract” among women to keep the value of sex high so as to hold a bargaining chip over men. Women who are promiscuous violate this contract and are penalized by other women.


    I hope this essay explains why men and women think differently. I’m happy to hear corrections/suggestions/ideas for improvement.


    1. http://emilkirkegaard.dk/en/wp-content/uploads/David-M.-Buss-Handbook-of-Evolutionary-Psychology.pdf

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