Via
Matt comes some more
interesting evidence about the neurobiology of sexuality, and the ways in which orientation may indeed be ingrained:
in gay people, key structures of the brain governing emotion, mood, anxiety and aggressiveness resemble those in straight people of the opposite sex. The differences are likely to have been forged in the womb or in early infancy, says Ivanka Savic, who conducted the study at the Karolinska Institute in Stockholm, Sweden. "This is the most robust measure so far of cerebral differences between homosexual and heterosexual subjects," she says.Previous studies have also shown differences in brain architecture and activity between gay and straight people, but most relied on people's responses to sexuality driven cues that could have been learned, such as rating the attractiveness of male or female faces. To get round this, Savic and her colleague, Per Lindström, chose to measure brain parameters likely to have been fixed at birth. "That was the whole point of the study, to show parameters that differ, but which couldn't be altered by learning or cognitive processes," says Savic.
The study is interesting, in that it tries to get around problems of neuroplasticity (i.e, that our brains change in response to our environment and life choices) by examining structural components that they don't think change over a lifetime. That's a good start, but the study I'd really be interested in reading would examine the brains of thousands of infants, or toddlers, and then survey orientation years into the future, and see what correlations you found.That said, like a lot of liberals, I believe that sexual orientation is largely nature, and if it's not nature, it's nurture in a manner so deep as to be essentially indistinguishable. But there's a part of me that's never understood the importance of this debate. It seems to cede the idea that there's something wrong with homosexuality, but because it's part of the biological makeup of folks, it's going to be too hard to correct, so might as well live with it. But insofar as people believe there's nothing wrong with being gay, they should believe there's nothing wrong with being gay! If folks want to choose that path at age 17, so be it. I've never read a convincing argument for how homosexuality inflicts harm on those exposed to it, or those who have to see it on primetime television, and as such,
why people do this thing that makes them happy and causes me no harm seems like an interesting question, but not one that's as relevant to setting national policy as some seem to imply.
Image used under a Creative Commons license from Philippe LeRoyer. 
