This piece was originally published on the Blowfish Blog.
So why do people do the sexual things they do?
And more to the point: If you have a theory about why people do the sexual things they do, how would you prove it?
There's an article in the New York Times that's been making the rounds, a piece about current sexology research and what it says about female desire. The bit that's getting the most attention is the research by psychology professor Meredith Chivers on different types of visual erotic stimulation (images of men and women doing it, images of two men doing it, images of two women doing it, images of solo men, solo women, monkeys, etc.), and which types aroused men compared to women. And what this says about male versus female sexuality. And what that says about how our sexualities evolved.
The data everyone's talking about, though, isn't so much about what kinds of dirty pictures women and men like to look at. (Although that is interesting and pertinent: if the research is correct, men tend to be aroused by a fairly narrow band of imagery that clearly correlates with their sexual orientation, while women tend to be aroused by imagery that's all over the map.) What's getting the attention is the stuff about how hard it is determine which images women are aroused by... because women's self- reported mental responses, and their involuntary genital responses, don't match up.
Now. Chivers' conclusion is that women are physically aroused by a broader range of visual stimuli because, due to evolutionary pressure, it behooves women to be physically ready for sex they don't want. To put it more bluntly: Women get raped. If women are physically aroused by a broad range of visual stimuli, we will be physically ready for sex even if we don't want it, and are thus less likely to be injured during rape. Thus increasing our chances of survival.
Okay. That's the preface. Here's what I want to talk about.
I want to talk about how difficult it is to draw useful conclusions about the evolutionary reasons behind any behavior. But especially sexual behavior, and behavior related to gender differences... since both sexual behavior and gender roles have heavy cultural baggage, and are the subject of intense social pressure, both conscious and unconscious, pretty much from birth.
So here's my argument.
Is Chivers' explanation plausible?
It could be that women's sexuality is more bound up with emotional attachment than men's... and emotional attachment is more complex than simple lust, with a wider range of potential objects.
It could be that women live in a culture steeped in imagery of sexual women, a culture where women are constantly presented as objects of sexual desire, and thus even straight women learn to see other women that way.
It could be that women's sexual desire is less gender- specific than men's. (There's some other data in the Times article backing up this theory.)
It could be that women are less aroused by visual erotic stimulation than other forms (such as verbal), and that showing women visual images isn't the best way to figure out what we're aroused by.
And it could be that women's sexual desire is more complex and multi-factorial than men's in many ways, with a less specific and more sweeping scope.
And why is women's self- reported mental arousal less likely than men's to match our measured genital arousal?
It could be that women are taught from birth to be disconnected from our bodies and our sexuality, so we don't find it as easy to identify our genital sexual responses.
It could be that women are taught from birth that being sexual is dirty and bad, and so aren't as comfortable speaking frankly about it as men. In other words, women don't want to admit what it is that's turning them on. (Even to themselves. See above.)
It could be that male physical arousal is easier to notice -- what with the boner and all -- and thus men are more likely to define "arousal" as "genital arousal," and to self- report it as such.
It could be because of Chivers' "surviving rape" explanation.
And it could be, again, that women's sexuality is more complex and multi-factorial than men's, with a stronger "purely mental" component.
To be very clear: I'm not actually advocating any of these positions. I'm coming up with them to make a point. That point:
I could do this all day.
And I'm not sure how you would test any of these theories.
See, here's the thing. As evolutionary biologist PZ Myers points out, there are enormous problems with these sorts of evolutionary "just-so stories." They're very easy to come up with (fun, too!), but they're very difficult to test. You have to somehow screen out cultural influence (was the study done cross- culturally, or just in North America?). You have to screen out historical influence (if X behavior pattern is universal now, how do we know it was universal a thousand years ago, or thirty thousand?). And you have to screen out behaviors that are inborn from behaviors that are learned. As Chivers herself acknowledges, "The horrible reality of psychological research is that you can't pull apart the cultural from the biological."
And as any good skeptic knows: If a theory isn't testable or falsifiable, it's worthless. Whether it's a belief in God, or a conspiracy theory, or a simple theory about the evolutionary forces driving the development of certain sexual responses... if there's no possible data that could prove your theory incorrect, or no way to acquire further data either supporting or contradicting your theory, then your theory is useless. It has no power to explain the past or predict the future. It's pointless. It's not even wrong.
It's easy to come up with possible explanations for behavior. Especially when it comes to sex. It's almost like a Rorschach test: in the absence of a truly excellent set of supporting data, the theories people come up with to explain sex tells you more about the theorizers than they do about the theories.
It's a lot harder to come up with theories that are really supported by all the evidence; theories that explain and predict evidence that can't be explained or predicted any other way; theories that are more than just examples of the human brain's amazing ability to come up with explanations for stuff.
By all means, we need to be doing careful scientific research into human sexuality. I wouldn't in a million years suggest otherwise. We just need to be very cautious, very rigorous, and very slow, about coming to conclusions about what that research means.
These ideas were developed in a comment thread on Pharyngula.