I have asked Muslims I know what happens to all the men who miss out on getting a partner in an Islamic society when polygamy is practised? Assuming levels of homosexuality are constant across cultures and that the gender ratio is approximatetely 1:1, won't there be a lot of sexually frustrated men?
This article from Psychology Today suggests that frustration is inevitable and explains the concentration of terrorism and suicide bombers among Muslim polygamist societies as a consequence. The claim is that nearly all suicide bombers are single.
This is a corollary of the idea due to Robert Frank - discussed earlier on this blog - that polygamy favours females at the expense of males.
'The history of western civilization aside, humans are naturally polygamous. Polyandry (a marriage of one woman to many men) is very rare, but polygyny (the marriage of one man to many women) is widely practiced in human societies, even though Judeo-Christian traditions hold that monogamy is the only natural form of marriage. We know that humans have been polygynous throughout most of history because men are taller than women.
Among primate and nonprimate species, the degree of polygyny highly correlates with the degree to which males of a species are larger than females. The more polygynous the species, the greater the size disparity between the sexes. Typically, human males are 10% taller and 20% heavier than females. This suggests that, throughout history, humans have been mildly polygynous. Relative to monogamy, polygyny creates greater fitness variance (the distance between the "winners" and the "losers" in the reproductive game) among males than among females because it allows a few males to monopolize all the females in the group.
The greater fitness variance among males creates greater pressure for men to compete with each other for mates. Only big and tall males can win mating opportunities. Among pair-bonding species like humans, in which males and females stay together to raise their children, females also prefer to mate with big and tall males because they can provide better physical protection against predators and other males. In societies where rich men are much richer than poor men, women (and their children) are better off sharing the few wealthy men; one-half, one-quarter, or even one-tenth of a wealthy man is still better than an entire poor man. As George Bernard Shaw puts it, "The maternal instinct leads a woman to prefer a tenth share in a first-rate man to the exclusive possession of a third-rate one."
Despite the fact that humans are naturally polygynous, most industrial societies are monogamous because men tend to be more or less equal in their resources compared with their ancestors in medieval times. (Inequality tends to increase as society advances in complexity from hunter-gatherer to advanced agrarian societies. Industrialization tends to decrease the level of inequality.)
Most women benefit from polygyny, while most men benefit from monogamy When there is resource inequality among men—the case in every human society—most women benefit from polygyny: women can share a wealthy man.
Under monogamy, they are stuck with marrying a poorer man. The only exceptions are extremely desirable women. Under monogamy, they can monopolize the wealthiest men; under polygyny, they must share the men with other, less desirable women. However, the situation is exactly opposite for men. Monogamy guarantees that every man can find a wife.
True, less desirable men can marry only less desirable women, but that's much better than not marrying anyone at all.
Men in monogamous societies imagine they would be better off under polygyny. 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, a wife who is much less desirable than one they could get under monogamy.
Most suicide bombers are Muslim Suicide missions are not always religiously motivated, but according to Oxford University sociologist Diego Gambetta, editor of Making Sense of Suicide Missions, when religion is involved, the attackers are always Muslim. Why?
The surprising answer is that Muslim suicide bombing has nothing to do with Islam or the Quran (except for two lines). It has a lot to do with sex, or, in this case, the absence of sex.
What distinguishes Islam from other major religions is that it tolerates polygyny. By allowing some men to monopolize all women and altogether excluding many men from reproductive opportunities, polygyny creates shortages of available women. If 50% of men have 2 wives each, then the other 50% don't get any wives at all.
So polygyny increases competitive pressure on men, especially young men of low status. It therefore increases the likelihood that young men resort to violent means to gain access to mates. By doing so, they have little to lose and much to gain compared with men who already have wives. Across all societies, polygyny makes men violent, increasing crimes such as murder and rape, even after controlling for such obvious factors as economic development, economic inequality, population density, the level of democracy, and political factors in the region.
However, polygyny itself is not a sufficient cause of suicide bombing. Societies in sub-Saharan Africa and the Caribbean are much more polygynous than the Muslim nations in the Middle East and North Africa. And they do have very high levels of violence. Sub-Saharan Africa suffers from a long history of continuous civil wars—but not suicide bombings.
The other key ingredient is the promise of 72 virgins waiting in heaven for any martyr in Islam. The prospect of exclusive access to virgins may not be so appealing to anyone who has even one mate on earth, which strict monogamy virtually guarantees. However, the prospect is quite appealing to anyone who faces the bleak reality on earth of being a complete reproductive loser.
It is the combination of polygyny and the promise of a large harem of virgins in heaven that motivates many young Muslim men to commit suicide bombings. Consistent with this explanation, all studies of suicide bombers indicate that they are significantly younger than not only the Muslim population in general but other (nonsuicidal) members of their own extreme political organizations like Hamas and Hezbollah. And nearly all suicide bombers are single'.
Of course these arguments are a bit suspect when it comes to the welfare of women. If women are in scarce supply then extremely strict regtulations might be imposed by men to stop them exerting their market power. There are few societies on earth where women have a narrower range of options than Islamic societies.
Also if women must live with the consequences of terrorism - response attacks by those who don't like seeing their citizens blown to pieces by sexually frustrated bigots - then they will be disadvantaged anyway. I can't see women living with their homes being bombed and their sons and husbands being killed enjoying that much advantage irrespective of their monopoly power.
Excerpted from Why Beautiful People Have More Daughters, by Alan S. Miller and Satoshi Kanazawa, to be published by Perigree in September 2007. Among the other issues analysed are why men prefer blondes and women with blue eyes, why couples with at least one son divorce less frequently, why beautiful people have more daughters, and why male harrassment of women is not sexist.