Lesbians’ Brains Not Same

Lesbians’ brains are wired differently than those of heterosexual women, reports a new scientific study.

Homosexuals’ brains respond differently from those of straight men and women when exposed to sex hormones, but researchers now say the difference is less pronounced in lesbians than in gay men. Lesbians’ brains reacted somewhat, though not completely, like those of heterosexual men, a team of Swedish researchers said in Tuesday’s edition of Proceedings of the National Academy of Sciences. A year ago, the same group reported findings for gay men that showed their brain response to hormones was similar to that of heterosexual women. In both cases the findings add weight to the idea that homosexuality has a physical basis and is not learned behavior.

[…]

Heterosexual women found the male and female pheromones about equally pleasant, while straight men and lesbians liked the female pheromone more than the male one. Men and lesbians also found the male hormone more irritating than the female one, while straight women were more likely to be irritated by the female hormone than the male one.

All three groups rated the male hormone more familiar than the female one. Straight women found both hormones about equal in intensity, while lesbians and straight men found the male hormone more intense than the female one. The brains of all three groups were scanned when sniffing male and female hormones and a set of four ordinary odors. Ordinary odors were processed in the brain circuits associated with smell in all the volunteers. 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. In straight women the sexual area of the brain responded to the male hormone while the female hormone was perceived by the scent area. In lesbians, both male and female hormones were processed the same, in the basic odor processing circuits, Savic and her team reported.

Each of the three groups of subjects included 12 healthy, unmedicated, right-handed and HIV-negative individuals.

As always with these studies, I am baffled that scientists publish findings based on such tiny sample sizes. Further, while I tend to believe homosexuality is indeed wired in the brain rather than a simple “lifestyle choice,” it’s not at all clear to me how this study sheds any light on the subject. After all, no one doubts that homosexuals are more attracted to people of the same sex than heterosexuals.

Echidne shares my questions about the survey.

More generally, that something shows up in the brain does not tell us that it always showed up in the brain the same way. Experiences we have (such as depressive illnesses) can change the way the brain reacts. What if having sex with a certain sex changes the way your brain reacts? Note that I’m not arguing against homosexuality having a physical basis. I’m arguing against the increasingly common assumption that brain scan differences are proof for a genetic explanation of behavior. Think about people who are bilingual. Their brains scan differently than the brains of monolinguals but the second language is certainly learned.

She gives her own anecdotal account of essentially “losing” her ability to differentiate the smells of cooking meats after conversion to vegetarianism.

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James Joyner
About James Joyner
James Joyner is Professor and Department Head of Security Studies at Marine Corps University's Command and Staff College and a nonresident senior fellow at the Scowcroft Center for Strategy and Security at the Atlantic Council. He's a former Army officer and Desert Storm vet. Views expressed here are his own. Follow James on Twitter @DrJJoyner.

Comments

  1. ICallMasICM says:

    ‘Lesbiansâ?? brains are wired differently than those of heterosexual women’

    There’s news

  2. LJD says:

    Experiences we have (such as depressive illnesses) can change the way the brain reacts.

    Or to make a baseball analogy, if you eat a lot of hot dogs, you likely prefer the smell of hot dogs. Or if you eat a lot of apple pie…

  3. Phil says:

    Regarding the “baseball” analogy…

    You are not likely to eat a lot of hot dogs or apple pie to begin with unless something about them already appeals to you. The response of the brain is to reinforce an existing attraction, not change the attraction.

  4. LJD says:

    So forget the fact that this study included a total of thirty six people. Forget the fact that their responses ranged from ‘pleasant’, to ‘liked’, to ‘irritated’, and even ‘intense’ or not. Forget the fact that there was no mention of the ‘other’ scents used and what the response was. For all we know, a similar response was reached for fresh-from-the-oven pizza, or limburger cheese.

    It is a far jump to say that gay men’s brains ‘worked’ more like a woman’s, or a gay woman’s brain ‘worked’ more like a man’s. Unless of course, that reinforces your steroetypes or belief in ‘genetic coding’. Then you can just believe whatever you want. Like all lesbians prefer feminine women over butches, and all gay men prefer manly men over drag queens. Right…

  5. Tano says:

    I think that the criticism of this study is misplaced. It is a scientific study of how the brains of these people work. I havent read the whole paper, but from the excerpts given here, I dont see any attempt to present these findings as some remarkable milestone in the political debates surrounding these issues.

    It is you guys who operate in the politcal arena who seem to have the attitude that anything and everything that is published on an issue that has political implications, must be judged in terms of how it effects the debate. Thus this study is to be dismissed because it fails to offer some decisive verdict that can clarify the political issue.

    But it doesnt seem to have been trying to do anything of the sort. We may all “know” that homosexuals are more attracted to the same sex than to the other, but how does that actually work physiologically? From a biologists point of view, this is a perfectly good and interesting study that demonstrates how the brain reacts to pheromones, and does so differently in those groups. I didnt see any claim that this speaks to the issue of whether those differences are genetically based – and there is no reason why a study like this needs to address that issue. Its a fascinating issue, but this is just one small, and important study that clarifies one small and important process.

  6. Ah, what passes for science these days. Hmmm…, if their brains are different then they cannot be the same. If the cannot be the same, then one must be “better” than the other, however you might choose to define that. Do we really want to go there?

  7. LJD says:

    Well Tano, I find it interesting that some one with your values would think that ‘these peoples’ brains all work the same, or that they are ‘different’ from any other human being.

    If you don’t think there is political motivation behind a study to connect physiology and sexual preference, then you can’t see the forest for the trees.

    BTW, you totally made my point with Phil about believeing what you want about a flawed ‘study’.

  8. Tano says:

    Charles,

    Could you please point to any place in the actual study where there is a claim of something being “better” than anything else.

    Failing that, I think your remark is absolutely stupid, and absolutely dishonest.

  9. Tano says:

    LJD writes,

    “I find it interesting that some one with your values would think that â??these peoplesâ?? brains all work the same, or that they are â??differentâ?? from any other human being.”

    Huh? What do you know of my values? And where on earth do you get the idea that I think either of those two things? Do you have the slightest idea of what you are talking about?

    How does attraction work physiologically? What, if any, are the reactions in the brain that can be measured when one is exposed to pheromones? How is that different in groups that experience different types of attraction? You don’t have to be a biologist to figure out that these are interesting biological questions, that any physiologist would be interested in exploring.

    I don’t think that you have the slightest interest in science, or knowledge in general – at least you don’t seem to exhibit any such interest. Your assessment of whether a study is “flawed” is less than useless.

  10. Sorry, soft “science” studies that posit corelation as causation do not interest me enough to read them.

  11. And anyway, I think you missed my point entirely. Engineering, disengage.

  12. Tano says:

    Hey Charles, good for you – you have picked up on the corelation [sic] vs. causation meme. It is a totally valid issue in the hands of someone who actually reads scientific papers and can figure out what they are, or are not saying.

    So I will give you another chance. Please point to the causal claim made in the paper that is deserves to be subject to this objection.

  13. 1. Sorry, correlation. Just a typo, in case you were wondering, although I’m sure you think I don’t know the difference. Vive la difference!

    2. Good one, although I picked up on the correlation vice (not versus, incidentally) causation meme about 20 years before meme became the latest overused catchword amongst the cognoscenti.

    3. I never said the study said what you said I said it said. But if you have to explain the joke it’s not very good.

    4. There is no #4.

    5. I don’t need another chance. Check the last post again, I’m not playing. Especially with someone who just knows they know more about this or anything else than I do based upon one flippant remark.

    6. If my brain works differently than a heterosexual woman, does that mean that I’m a lesbian trapped in a man’s body?

    7. Under the influence of what pedagogical theory did you derive the idea that straw men, sorry, straw people, non sequiturs and ad hominem attacks constitute reasoned discourse? Such a diabolical dialectic.

    8. I humbly apoligze to Mr. Joyner for straying so far afield.

  14. LJD says:

    I conducted my own ‘scientific study’ including two respondents.

    What did one lesbian frog say to the other lesbian frog?

    You know, we DO taste like chicken.