Was macht evolutionäre Erklärungen besser als die soziokulturellen Erklärungen?

Aus einem Interview mit dem Evolutioonsbiologen Steve Steward Williams:

LC: You spend some time rebutting the criticism of evolutionary explanations that say they are “just-so stories.” In general, what makes evolutionary explanations of human psychology better than their sociocultural competitors?

SSW: Well, the only thing that makes any explanation any good is that it’s true! So, there are plenty of evolutionary explanations that I think are worse than their sociocultural competitors, just because the sociocultural explanations are more accurate. In my view, for example, cultural explanations of religion are more accurate than evolutionary ones. The evolutionary explanations overextend the adaptationist mode of explanation—a mistake the paleontologist Stephen Jay Gould dubbed panadaptationism.

At the same time, though, evolutionary explanations are often better than explanations that chalk everything up to sociocultural factors, for the simple reason that—in these cases—the evolutionary explanations are more accurate. This is true, for instance, when it comes to sex differences in interest in casual sex, sex differences in aggression, certain mate preferences, incest aversion, and kin favoritism. Various lines of evidence suggest that these things have an evolutionary origin: They’re found across cultures; they’re resistant to social influence; they’ve been linked to prenatal hormonal exposure; and they’re found in many other species—species that are subject to similar Darwinian selective pressures as humans. Culture may help to color these tendencies, channel them, magnify or minimize them. But their ultimate origins lie in our evolutionary past.

Und diese Stelle passt dazu auch noch, weil sie quasi ein konkreter Anwendungsfall ist:

I began work on the book in 2013, shortly before I started noticing this latest resurgence of science denial—and in particular, the denial of the reality of sex differences. In many ways, this is just a resurgence of 1970s-era gender silliness. It’s quite frustrating, though, because just as I thought we were finally putting these ideas behind us, we’ve been sucked straight back into the morass. And although it’s not new, it does seem to have come back with a vengeance.

Actually, I should add that, although much of it is not new, some aspects are. In particular, the denial that male and female are even valid concepts, and the claim that sex is a spectrum rather than a binary, is quite a novel departure. And it’s quite amazing and frightening how willing so many people are to go along with something so utterly radical and discrepant with common sense, let alone with biological science. So, let me say a little about sex and gender.

According to biologists, sex is ultimately about the kind of sex cells an individual produces. Individuals with the body type that produces the smaller sex cells (sperm) are male; those with the body type that produces the larger sex cells (eggs) are female. Humans only produce two types of sex cells, and thus there are only two sexes in our species.

Now, that doesn’t mean that everyone fits tidily into the male or female categories. Most people do, but a small number don’t; they’re intersex. Intersex people are not easily categorized as male or female in terms of their chromosomes, their anatomy, their brain anatomy, or their sense of themselves as men or women. This doesn’t change the fact, though, that there are only two sexes in our species; intersex isn’t a third sex, because intersex people don’t produce a third type of gamete. Two sexes is what selection favoured.

Of course, there’s a lot of psychological variation within both sexes. Does that imply that sex is a spectrum, rather than a binary? No. Masculinity and femininity are spectrums, but sex is not. And no one ever thought that all men are equally masculine or that all women are equally feminine. We’ve always known that men and women differ in terms of how masculine and feminine they are. It’s strange that people now want to say that this variation implies that actually only the most stereotypically masculine men are fully men, and only the most stereotypically feminine women are fully women, and that everyone else lies somewhere in between. The whole idea involves quite extreme stereotyping about what it means to be a man or a woman! It seems much more sensible to me to say that there are two sexes in our species, that the vast majority of people are easily categorised as one or the other, and that people belonging to each sex vary greatly in terms of both masculinity and femininity (although there are also average differences between the sexes in these traits—differences that are partially innate).

We can accept all of this while fully supporting the rights of transgender people and respecting their dignity as human beings.