The Mating Game Theory

One of the fascinating things about Social Media (of all types) is you can see theories about how humans work being played out in highly numerate (ie measurable and thus calculatable) ways. Take the game teory of "dating". Sociobiologists long ago cracked the theoretical maths (to universal opprobrium from more sensitive but less numerate "ology" disciplines) - and game theorists have now descended into the details of sperm war - but actually seeing it in play (as it were) from dating site data is fascinating - here is OKCupid's analysis.

The key slide is the one above - relative attractiveness potential of men and women as they age - in essence women are far more attractive than men in their 20's but then their attractiveness declines while men's rises and then declines more slowly. This drives nearly all the game theory of the "battle between the sexes"

The reason, as evolutionary and socio biologists and various similar disciplines will tell you - is the whole issue of reproduction - younger women are more likely to bear and be able to bring up healthy kids, older men more likely to have the resources to pay for them. I won't get into the functions of infidelity here, go read sperm wars instead

The key analysis on what happens because of this disparity is this piece of game theory - the Eligible-Bachelor Paradox

If we imagine the search for partners as an auction, some of us are more confident of our long term prospects than others. People with brains, looks, social capital, money, or any combination of any of them can afford to be selective. Men and women who are traditionally thought of as desirable partners can be thought of as strong bidders. People who are less confident of their prospects are known as weak bidders.

In the marriage market, there is an enormous incentive to get it right the first time. Consequently, weak bidders will move into the market very aggressively, while strong bidders stand pat, looking for a really good deal. Those who are most confident of their prospects are most likely to prolong their search for the perfect partner.

Our traditional model, where the male makes the marriage proposal and the female gives the thumbs-up or thumbs-down, places most males in the position of a weak bidder (especially when young - see above graph). If his proposal is rejected, his social capital is devalued, especially if word gets around, and it certainly will. Therefore, more men are weak bidders than women. For a suitor, success is defined as getting a positive response, and he would rather get an acceptance from a marginally desirable prospect than a rejection from a very desirable prospect.

In short, the outcome is that the pool of appealing men shrinks as many are married off and taken out of the game, leaving a disproportionate number of men who are notably imperfect (perhaps they are short, socially awkward, underemployed). And at the same time, you get a pool of women weighted toward the attractive, desirable "strong bidders."

Where have all the most appealing men gone? Married young, most of them—and sometimes to women whose most salient characteristic was not their beauty, or passion, or intellect, but their decisiveness.

Incidentally, Robin Dunbar (he of the Dunbar number) has also been looking into this area, and here is a BBC writeup of his worK:

Dunbar found that the vast majority of words used by people to describe themselves in ads could be lumped into five different categories.

He asked 200 university students to rate the appeal of ads containing different categories of words. When Dunbar analysed the results, he found that men and women attached very different levels of importance to the five categories:

Men's preferences Women's preferences

1. Attractiveness 1. Commitment
2 Commitment 2. Social Skills
3. Social Skills 3. Resources
4. Resources 4. Attractiveness
5. Sexiness 5. Sexiness

Far from being conditioned to regard these things as important, Dunbar argued that men and women had evolved these preferences over millions of years of evolution. These were crucial qualities that enhanced the fitness of children, and, lest we forget, children are the key to the survival of our species.

As to the all important quesion of "when to put out" consider this:

The research in the Journal of Theoretical Biology uses game theory to analyse how males and females behave strategically towards each other in the mating game. The mathematical model considers a male and a female in a courtship encounter of unspecified duration, with the game ending when one or other party quits or the female accepts the male as a mate. The model assumes that the male is either a ''good'' or a ''bad'' type from the female's point of view, according to his condition or willingness to care for the young after mating.

The female gets a positive payoff from mating if the male is a ''good'' male but a negative payoff if he is ''bad'', so it is in her interest to gain information about the male's type with the aim of avoiding mating with a "bad" male. In contrast, a male gets a positive payoff from mating with any female, though his payoff is higher if he is "good" than if he is "bad".

The study looks for evolutionarily stable equilibrium behaviors, in which females are doing as well as they can against male behavior and males are doing as well as they can against female behavior. It shows that extended courtship can take place, with a good male being willing to court for longer than a bad male and the female delaying mating. In this way the duration of a male's courtship effort carries information about his type.

By delaying mating, the female is able to make some use of this information to achieve a degree of screening. Because bad males have a greater tendency to quit the courtship game early, as time goes on and the male has not quit it becomes increasingly probable that he is a "good" male.

But leave it too long and they are in Eligible-Bachelor Paradox territory, and risk being passed on.....

One of the things I've been wanting to see is the impact of female economic emancipation, as that changes the game hugely and is very recent in earth's biology - ie if a woman no longer needs the resources of the man to bring up the offspring, her choice of optimal male will change (did someone say Cougar.... ?). I haven't seen much data analysis of that game, apart from this piece arguing that men enjoy marriage and women don't.

Still, the OKCupid article is still a very interesting article, give it a read. (Hat tip Hadley Beeman for the pointer)