naturalistic fallacy,

the tendency to believe that what is natural is good;

moralistic fallacy,

This is the tendency to believe that what is good is natural; that what ought to be, is.

you cannot dismiss an observation by calling it a stereo type,

Many stereo types are empirical generalizations with a statistical basis and thus on average tend to be true.

there is no place for “ought” in science.

Even though we live in the twenty-first century, we have a Stone Age brain ( just like we have Stone Age hands and a Stone Age pancreas).

If our brain truly comprehended supermarkets, we would not crave sweet and fatty foods.

Evolution cannot work against moving targets.

According to this explanation, men and women (and boys and girls) think and behave differently because they have been socialized differently by their culture and society.

A variable cannot explain a constant; only a constant can explain a constant.

men and women are hardwired to be different.

men and women are not different because they are socialized differently; they are socialized differently because they are different.

It takes a woman at least nine months, usually a few years, to produce one child (because a woman is usually infertile while she nurses her baby); it takes a man fifteen minutes.

Fitness variance is the difference between the “winners” and the “losers” in the reproductive game—how much more reproductively successful the winners are compared to the losers. Because of anisogamy and internal gestation, men have much greater fitness variance than women.

Under polygyny, some men get more than their “fair share” of mates, leaving others with none.

As we will discuss repeatedly throughout this book, the greater fitness variance among men, rather than gender socialization, is the reason why men are much more aggressive, competitive, and violent than women.

The potential benefit of competition does not justify the potential costs (injury or death). This is why women are on the whole not as aggressive, competitive, or violent as

The much higher fitness ceiling for men than for women also means that women make a far greater investment into their children than men do.

However, all the cultural differences are on the surface; deep down, at the most fundamental level, all human cultures are essentially the same.

This is probably why blonde hair evolved in cold climates as an alternative means for women to advertise their youth.22

to allow men to have intercourse with women? If men’s brains truly comprehended that they would likely never have sex with the naked women in pornography, they would not get an erection when they watch it. The Savanna Principle applies equally

Women avoid pornography for the same reason that men consume it; in both cases, their brains cannot really distinguish between real sex partners and the imaginary ones.

(Recall the dangers of moralistic fallacy from the introduction. The fact that marital fidelity is a virtue means neither that it is natural for us nor that we are always faithful to our spouses.

If human females did not engage in extensive extra-pair copulations throughout human evolutionary history, the human penis would not be shaped as it is,

Clear evidence of women’s promiscuity throughout evolutionary history is in the size and shape of men’s genitals and what men do with them.

This suggests that, throughout evolutionary history, humans have been mildly polygynous, not as polygynous as gorillas but not completely monogamous like gibbons either. This is how we know that humans are naturally polygynous.

The greater fitness variance among males creates greater pressure for men to compete with each other for mates.

while most or all females of all sizes reproduce and pass on their full range of sizes to their daughters.

Under monogamy, most adult males are already married and cannot marry again, so there are no incentives for prepubescent girls to mature earlier; prepubescent boys in their age group are in no position to marry them. In contrast, under polygyny, married adult males can acquire additional wives.

In societies with a high degree of resource in equality, where rich men are very much richer than poor men, women (and their children) are better off sharing the few wealthy men,

All Human Societies Are Polygynous, Simultaneously or Serially

wealthier men in the United States and Canada have more sex partners and have sex more frequently than less wealthy men.30

In the United States, the strongest predictor of remarriage after divorce is sex (male vs. female): men typically remarry, women typically do not.

under polygyny, women can share a wealthy man, whereas under monogamy, they are stuck with marrying a poorer man.

Most men benefit from monogamy, because it guarantees that every man can find a wife.

What they don’t realize is that for most men, who are not extremely desirable, polygyny means no wife at all, or, if they are lucky, one wife who is much less desirable than one they could get under monogamy

Flowers, another favored gift for women, are also relatively expensive and lack intrinsic value. Of course, diamonds and flowers

Since brain types are heritable, the generalized Trivers-Willard hypothesis would predict that parents with strong male brains, such as engineers, mathematicians, and scientists, are more likely to have sons,

While the sex ratio at birth among the general population is 0.5122—that is, 105 boys for every 100 girls—the study shows that the sex ratio among engineers and other systemizers is 0.5833—that is, 140 boys for every 100 girls.

Over many generations throughout evolutionary history, genes that make babies resemble the father therefore survive, whereas genes that make them resemble the mother do not, and so more and more babies come to resemble the father, until most babies are born resembling the father, not the mother.

get their last names from the father, not the mother. By giving their children the father’s last name, these women are essentially (albeit unconsciously) saying, “Honey, it’s yours” (even, or especially, when

Because women prefer to mate with men of high status and good reputation,9 a man’s status and reputation directly correlates with his reproductive success.

Predatory rapists are overwhelmingly men of lower class and status, who have very dim prospects of gaining legitimate reproductive access to women.10

It is therefore imperative for mothers rather than fathers to survive long enough to take physical care of their offspring to ensure their survival to sexual maturity. This, Campbell argues, is why females are more risk-averse than males are.

being competitive might result in their death or injury, and they might therefore lose in the reproductive game if they are too competitive.

The cost of competition, however, rises dramatically with the birth of the first child and subsequent children.

There is therefore a gap of several years between the rapid rise in the benefits of competition and the similarly rapid rise in its costs.

In all species in which the female makes greater parental investment than the male (such as humans and all other mammals), mating is a female choice;

There would be no civilizations no art, no literature, no music, no Beatles, no Microsoft, if sex and mating were a male choice. Men have built (and destroyed) civilizations in order to impress women so that they might say yes. Women are the reason men do everything.

“Why on earth would the most powerful man in the world jeopardize his job for an affair with a young woman?” is a silly question. Betzig’s answer would be: Why not?