It’s been too long since I last unpacked an example of bad science (or of bad reporting of science, it is sometimes difficult to say which). Jacalyn sent me the url for an article on a new study: “Lesbians’ brains respond like straight men.” Now, what does this mean, exactly? In what way do lesbians’ brains respond like the brains of straight men? First of all, we are given no indication of how the survey defined “lesbians” and “straight men”; if they used peoples’ own self-definition, that is well and good from a sociological standpoint, but it is way too vague to stand as a biological category. Do they mean to imply that, if somebody’s self-definition changes, say if I stop defining myself as a straight man (which I am very often tempted to do, because of all the baggage that comes with the phrase “straight man,” baggage which goes very far beyond the accurate but fairly vague observation that most of the time I am more likely to be turned on sexually by women than by men), then their hormones suddenly change? But that is getting ahead of myself. We also have to ask, when lesbians’ brains “respond” like those of straight men, to what are they responding? Well, the article says, “lesbians’ brains react differently to sex hormones than those of heterosexual women… Lesbians’ brains reacted somewhat, though not completely, like those of heterosexual men.” Now, isn’t there something circular going on here? “Sex hormones” are defined later in the article as “pheromones” — but this is itself a category that far too little is known about, and that is so dubious, especially in human beings, that making generalizations on their basis is unacceptable to begin with; the article itself notes in passing that “whether humans respond to pheromones has been debated.” But even if we accept the pheromones, all the research is saying, really, is that lesbians and “straight men” are both more sexually attracted to women than to men; which is of course the tautology that the survey presupposed in the first place. Oh, I should add that the physiological correlate of this arousal is that the scent which someone finds sexually arousing is processed in a different part of the brain (the hypothalmus) from the normal scent-processing areas. So again all we have is a tautology, the repetition of what was presupposed at the beginning. Of course the arousal is taking place on a subconscious level, by the scents of pheromones themselves, without the test subjects knowing which gender’s scent they are smelling. But this was also presupposed in the initial plan of the study; it’s just another tautology. (I should also note that the idea that biological males and females have completely separate pheromonal scents, which supposedly do not overlap, or show enough variation to undo the rigid binary, is also being unwarrantedly presupposed). However, even this is not quite accurate as a basis for the alleged “similarity” between “lesbians” and “straight men.” The report notes that “ordinary odors were processed in the brain circuits associated with smell in all the volunteers.” However, “in heterosexual males the male hormone was processed in the scent area but the female hormone was processed in the hypothalamus, which is related to sexual stimulation.” Whereas in lesbians, “both male and female hormones were processed the same, in the basic odor processing circuits.” But wait: if this is the case, then they entire claim of the study, that lesbian brains respond somewhat like straight male brains, collapses. Lesbian brains (I have given up putting up scare quotes just out of laziness; of course they should be present each time any of these pseudo-categories is mentioned) are similar to straight male brains in terms of what both categories of brains share with straight female brains — they all process scents of the gender they aren’t aroused by in the ordinary “odor processing circuits.” But lesbian brains, unlike straight male brains, do not process the odors of the gender they are attracted to in the hypothalmus. Therefore, by the study’s own terms, and even accepting their dubious categories, the entire parallel between “lesbians” and “straight men”collapses.
I could go on, but this is probably enough. The largest claims the study makes, according to the article, are that “there are biological factors that contribute to sexual orientation,” and that “homosexuality has a physical basis and is not learned behavior.” The first of these is something that nobody of any sense would ever doubt; since to doubt it you would have to think that the mind is entirely disconnected from the body, to a degree that even Descartes never maintained. And the second statement is utterly nonsensical, since any behavior whatsoever has a “physical basis” by definition (if it had no physical basis, in what sense would it even exist? what would it mean to observe it?), regardless of whether it is “learned” or innate, or something else (I am not convinced that learned vs. innate is a meaningful duality to begin with, since there is so much overlap between the two terms, and since you have to define them way too broadly in order to eliminate other possibilities, and include every observation on either one side of the duality or the other).
The thing is, a “scientific” report or study this idiotic, this devoid of any meaningful terms, or real scientific basis, can be found in the press every week. All it shows, basically, is that people (both scientists and news reporters and, probably, the general public) “want to believe” that everything in human life has a “genetic” basis (something else that is way too ill-defined to pass muster), and that the “common sense” prejudicies of our culture are true. At the start of Western science, empiricist mocked the old philosophy’s explanation of opium’s power to put people to sleep by its being alleged to have a “dormative virtue.” But today human genetics seems itself to be entirely based upon the positing and proclaiming of such imaginary virtues and essences.
The next time I post, this blog will return to its usual programming.
You really could go on. I find it hard to believe responses to “sniffing” being valid at all. That statement alone invalidates the entire Porn industry.
Did you read the PNAS article or just the AP account?
I just read the AP account. Which is why I begin with a question as to whether it is a question of “bad science” or “bad reporting of science.” I am most interested in, precisely, the way all this work enters public discourse and consciousness — even if such entry is based on a misrepresentation of the actual scientific work. In general, I trust scientists more when they are actually doing stuff in the laboratory than when they give voice publicly to What It All Means.
I’ve read the paper and a previous one focused on male homosexuality, and the problem to me would be the lack of understanding of neural anatomical functioning and how the MRI is still a crude device to measure it. Here’s a passage from the first paper addressing this issue:
I think that if you read the articles in question, you’ll see that the language of the experiment is much closer to what we think of as hypothesis rather than tautology.
And PET as well.
Steve,
Have you ever thought about podcasting your lectures?
This is a potential mine field. Think of what happened to Larry Summers at Harvard.
Bad science, or bad politics?
It seems more like you’re the one doing the “bad science”… or rather, not much science at all. Most of your critique is a semantics game. You explain away what appears to be an interesting and potentially significant correlation as “tautology,” attempt to argue it’s impossible to distinguish instinctual behaviour from learned (and so why bother at all), make meaningless semantic arguments about the “physical basis” of behaviour (I think we all know what they meant when they said it) and then complain that scientists are trying to make everything seem genetic in origin because people “want to believe” it. Ascribing political motives to scientists, tsk tsk.
If we want to ascribe political or cultural motive to the article, I’d argue the article is doing just the opposite – attempting to justify a behaviour that most people still regard as abnormal and redefining it as natural because of its genetic basis. If homosexuality isn’t an instinctual drive, then it makes sense that it can be discouraged by society at large. If this is so, there are plenty of good arguments for such a policy (the biggest being a society totally composed of homosexuals can’t reproduce itself, and the less of a bad thing you have the better), but there I go again, attempting to define and categorize things by how people self identify… naughty me.
I think it’s possible that self identified homosexuals are partially influenced by a combination of genetics and culture, and biology forms itself from the former and adapts itself to the latter.