The Red Queen_ Sex and the Evolution of Human Nature - Matt Ridley [90]
That is not to say that homosexuals do not long for stable intimacy, or even that many are morally repelled by anonymous sex. But Symons’s point is that the desire for monogamous intimacy with a life companion and the desire for casual sex with strangers are not mutually incompatible instincts. Indeed, they are characteristic of heterosexual men, as proven by the existence of a thriving call-girl or ‘escort’ industry that, at a price, supplies happily married men with sexual diversions. Symons is commenting not on homosexual men, but on men in general. As he says, homosexual men behave like men, only more so; homosexual women behave like women, only more so.13
Harems and Wealth
In the chess game of sex, each gender must respond to the other’s moves. The resulting pattern, whether polygamous or monogamous, is a stalemate, rather than a draw or a victory. In elephant seals and sage grouse, the game reaches the point where males care only about quantity of mates and females only about quality. Each pays a heavy cost, the males battling and exhausting themselves, and dying in the often vain attempt to be the senior bull or master cock, the females entirely forgoing any practical help from the fathers in rearing their children.
The chess game reaches a very different stalemate in the case of the albatross. Every female gets her model husband; they share equally the chores of raising the chick, and even courtship is a somewhat mutual affair. Neither gender seeks quantity of mates, but both are after quality: the hatching and rearing of one solitary chick that is pampered and fed for many months. Given that male albatrosses have the same genetic incentives as male elephant seals, why do they behave so differently?
The answer, as John Maynard Smith was the first to see, can be supplied by game theory, a technique borrowed from economics. Game theory is different from other forms of theorizing because it recognizes that the outcome of a transaction often depends on what other people are doing. Maynard Smith tried pitting different genetic strategies against each other in the same way that economists pit different economic strategies against each other. Among the problems that were suddenly rendered soluble by this technique was the question of why different animals have such different mating systems.14
Imagine a population of ancestral albatrosses in which the males were highly polygamous and spared no time to help rear the young. Imagine that you were a junior male with no prospect of becoming a harem master. Suppose that, instead of striving to be a polygamist, you married one female and helped rear her offspring: you would not have hit the jackpot, but at least you would have done better than most of your more ambitious brothers. Suppose, too, that by helping your wife to feed the baby you greatly increased the chance that the baby survived. Suddenly, females in the population have two options: to seek a faithful mate like yourself or to seek a polygamist. Those that seek a faithful mate leave behind more young, so in each generation the number willing to join harems declines and the rewards of becoming a polygamist fall with it. The species is ‘taken over’ by monogamy.15
It works in reverse, as well. The male lark bunting of Canada sets up a territory in a field and tries to attract several females to breed with him. By joining a male that already has a mate, a female forfeits the chance to make use of his skills as a father. But if his territory is sufficiently richer in food than his neighbour’s it still pays her to choose him. When the advantage of choosing a bigamist for his territory or genes exceeds the advantage of choosing a monogamist