What makes women so goddamn picky about the people they're willing to have sex with, even though it seems eminently reasonable that they should toss it up to anyone who wants it?
A study by Dustin Penn of the Konrad Lorenz Institute for Ethology in Austria and Ken Smith of the University of Utah offers some tantalizing hints, so long as you don't mind the fact that it's based on data pertaining to Mormon couples who got married between 1860 and 1895.
When it comes to humans, women are naturally thought to suffer fitness costs from reproduction, given the stresses of pregnancy, childbirth and breast-feeding, but evidence for whether men do has been mixed and controversial....That's not quite clear, since at least one of the traditional criteria for female "choosiness" (reproductive vim and vigor) seems in this case to result not only in early mortality for the mother, but a poor prognosis for her offspring:
Penn and Smith found that having more children was linked with decreased survival for both parents, although this effect was more pronounced in women. After age 50 the number of offspring had no effect on the likelihood that fathers would die, but continued to have an impact on the mortality of mothers. This difference in cost between men and women fits with evolutionary explanations for the observation that women tend to be choosier than men when selecting mates.
[T]he more offspring parents had, the less likely each child was to survive to reproductive age.I'd say that the conclusions one can draw about Womanhood from the matrimonial hazards of 19th-century Mormonism are limited at best. Nonetheless, Smith and Penn suggest that their findings "shed light on the evolution of menopause...which humans experience but chimps and many other species do not." (Click here for research on menopause in guppies, and here for information on factors potentially affecting menopause in nonhuman primates, including diet and lifespan).
As you can see, it's all very...rigorous:
"One of the other problems we've been trying to explain in human reproduction is why women all over the world have been having fewer children whenever they get access to contraception or more education," says Dr. Penn.One might do better to study why women so often tend not to get access to these things, which is really a far more interesting question, and possibly even has some bearing on the problem that's worrying Dr. Penn.
Earlier today, I took issue with Amanda's claim that "animals are not different from us in any major way." This research is a good example of how overlooking little instances of human exceptionalism like culture, law, religion, and education complicates the "objective" study of our throbbing biological urges:
"If women bear a higher cost for reproduction than men, then this might help explain why, when they get control over their reproduction, they would have fewer children."I find it odd that people are looking for biological theories to explain what happens when women, by some unacknowledged process, "get control over their reproduction." Perhaps we can study the puzzling flight reaction of people whose prison doors are left unlocked, while we're at it.
Intriguingly, an environment in which resources were scarce, such as that faced by preindustrial Mormons, may have placed selective pressures on the innate psychology of women that at least partly explain why birth rates are so low in modern industrialized societies.Let me put this as politely as I can: I see no obvious reason why resource scarcity among communities in past centuries - communities that had limited access to sex education and contraception, mind you, as well as religious and social injunctions against both - should've created "selective pressures" favoring low birth rates in modern industrialized societies.
But what do I know? My brain is mostly female.
UPDATE: For those who didn't notice, the first sentence of this post was intended as a joke. It's obvious that "the stresses of pregnancy, childbirth and breast-feeding" take a greater toll on women than on men. What's less obvious is the extent to which female choice is actually permitted in a specific culture or community - most readers have heard of arranged and forced marriages, I'm sure - and the extent to which being free to choose one's mate (or let one's genes choose him) affects reproductive costs. Female parental investment sounds a bit more explanatory than it actually is, IMO.