Earlier this year, an article (Savic & Lindstrom, 2008) came out in PNAS with some really compelling evidence that a) gay brains are different from straight brains, and b) those differences are not a result of learning. Why so much attention compared to past gay brain studies?
Past studies:
1. Cerebral (motor cortex & reward circuitry) responses to watching porn: gay men = straight women; straight men = gay women
2. Anterior hypothalamic activation when sniffing pheromones: gay men = straight women; straight men = gay women
Not very compelling since these were all perceptual tasks, and responses could have been due to either innateness or learning. So Savic and Lindstrom wanted to look at factors not directly associated with behavior: a) cerebral asymmetry and b) functional connectivity of left vs. right amygdalae.
The motivation for cerebral asymmetry came from other studies that showed:
- Anterior commisure: gay men/straight women > straight men
- Verbal tasks: gay men/straight women > straight men/gay women
- Visuospatial tasks: gay men/straight women < straight men/gay women
- Right-ear preference: gay men/straight women < straight men/gay women
The choice to compare left and right amygdalae was based on Larry Cahill’s work on sexual dimorphism in emotional memory.
What they found was that sexually dimorphic brain features differed within same-sex subjects depending on sexual orientation. Essentially, gay male brains (like straight female brains) did not show cerebral asymmetry while straight male brains (like gay female brains) had larger right hemispheric volume. The amygdala scans also showed that functional connectivity was more widespread from the left amygdala in gay men/straight women, and the right amygdala in straight men/gay women.
More acceptance for gays?
These findings have gotten a lot of attention because of their implications that homosexuality is innate. Is this really something that will bring gays wider acceptance?
My advisor, Dr. H, has an interesting take on this:
Many gays and lesbians have embraced the position that homosexuality is not a choice because they feel that less discrimination and prejudice will be forthcoming for something that is genetic, biological, or otherwise not a choice. But this is a fallacy. Why shouldn’t people’s lifestyle choices be just as respected as “choices” made by their DNA? This reminds us of what is called the “naturalistic fallacy”: Just because something occurs in nature (e.g., has a genetic component) doesn’t mean we should tolerate the expression of those behaviors. For example, criminality and sociopathy have a genetic component, yet we don’t tolerate these behaviors. Religious beliefs are often choices, yet we tolerate (and protect by law) religious diversity.
For a long time I’ve been undecided about the innateness of homosexuality because twin studies haven't held up the genetics argument and because there are incidences of situational homosexuality (gay prison sex). But in any case, why can’t we strive for acceptance even if it is a choice? Do we really believe that by demonstrating a biological origin of homosexuality that less prejudice will be forthcoming? What makes us think that we would find anymore acceptance than sociopaths, as Dr. H suggests? (For one thing, sociopaths are not law-abiding citizens and for another, I would like to think they are fewer in number.)
Until I took a job teaching social psychology this year, I was convinced that it wouldn’t really matter to the straight population whether being gay was biologically determined or not; we would still remain a persecuted minority. But the social psychologist, Elliot Aronson, (2008) has something to say in regards to the effect of an unchangeable status:
The psychology of inevitability can and does set up pressures to reduce prejudiced attitudes.
That is, the sooner individuals realize that interaction with a disliked group is inevitable and stable, the sooner prejudiced attitudes will begin to change. If homophobic individuals with gay family members/co-workers/friends/etc. realize that they will inevitably have to interact with a gay person and that sexual orientation cannot change, then they are presented with a state of cognitive dissonance: the behavior (interacting with a gay person) does not match up with the attitude (dislike of homosexuals). Thus, they can continue feeling angry or they can change their attitudes about homosexuals.
So according to Aronson, a biological cause of homosexuality will lead to more acceptance for individuals close to a gay person. But what about acceptance from the general population? Unlike race, sexual orientation can be hidden and gay men and women can go on living their lives fully integrated without ever revealing their sexual identity. Will continued media exposure be effective? Unfortunately, inevitability wasn’t built into the remote.
References
Aronson, E. (2008). The social animal (10th ed.). New York: Worth Publishers.
Savic, I. & Lindström, P. (2008). PET and MRI show differences in cerebral asymmetry and functional connectivity between homo- and heterosexual subjects. Proceedings of the National Academy of Sciences, 105, 9403-9408.
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