# Sexual dimorphism

This essay is going to upset a lot of people, so let's start with a statement of what it is about: it is an attempt to describe the systematically different behaviours of men and women, in sufficient detail that this can be represented by agents in a game world. It's trying to allow as broad as possible a range of cultures to be represented, so when I'm talking about what I consider to be behaviours of particular cultures, I'll say that.

Of course, I'm writing this from the view point of an old white male. It's not possible to write about these things from a totally neutral viewpoint, and every one of us will have prejudices.

OK? Let's start.

When a man and a woman have sex, there's a non-zero chance that the woman will get pregnant. There's a zero chance that the male will get pregnant.

A woman can typically give birth to of the order of twelve children in the course of her life, and each childbirth involves a non-zero risk of death. If modelling the sort of bronze-age-to-late-medieval cultures I'm generally considering, there are no available reliable methods of contraception, although their may be, for example, known spermicidal or abortifacient spells or potions. If it's abortifacient, that's pretty unpleasant for the woman, too.

Children, especially when young, are very vulnerable and need protection. Children with good protection are much more likely to survive to adulthood. Raising children involves a fair amount of work.

For all sorts of reasons, some of which are clearly cultural but others of which are fundamental, it's much easier for men to walk away from responsibility for their children than it is for women. For example, considering a pre-modern world, women would always know for certain which children were theirs, and men would not.

For a woman, consequently, the best breeding strategy is to have sex only with men who will be 'good fathers', where there are three essential parameters to "good fathers":

1. Desirable genetic traits;
2. Preparedness to stick around and share the work;
3. Ability to provide and protect.

The essential trade-off in the traditional western marriage is that the man gets to have sex, and the woman gets to have protection for her progeny.

Another significant point is that women's ability to bear children ceases at a much younger age than men's ability to father them.

## Why have sex at all?

If a character has 'having children' - the [**Ancestor**](intro.html#aspirations-and-goals) aspiration, in my typology - as their key aim, then they will want to have sex. But to have children in this sense is to have acknowledged children, so while a male character may be motivated to have multiple female partners, he will never the less have some degree of long term committment to them, and will want both to feel confident that the children are his and to be recognised by their father.

From the point of view of seeking to become an Ancestor, there is little benefit to the woman in having multiple partners, except in very harsh environments. It will be easier to give one partner confidence that all your children are his, and while a man can increase his number of potential progeny by having multiple wives, mistresses or other classes of long-term female sexual partners, a woman cannot.

## Why have children?

In modern Scotland, I have met a lot of women with a strong drive to have children for the sake of having children, where the best explanation they could give is that it's instinctual; it may be so. But beyond that, in many cultures children provide their (acknowledged) parents with care and security in their old age, may tend their graves and perform belief-related services after they die, and carry on their name and their stories into the future.

Not everyone wants to have children; in thinking about the driving aspirations of game characters, I view having children one of six potential key aspirations.

## Why else have sex?

Sex, done right, is an extremely pleasant pastime. Sex can also be used to create and maintain bonds of committment, to demonstrate social status, to defuse tense situations, and transactionally in many ways, both formal and informal.

For women, sex with other women carries with it no risk of pregnancy, so can be enjoyed or used for any of these purposes in very much the same way as it can by men; in other words, particularly for women, homosexual sex can be more lighthearted and carefree than heterosexual sex. To what extend our notions of homosexuality and heterosexuality are cultural I simply don't know. But because no children will result, a woman can afford to be more promiscuous with other women than she can with men.

## 
