February 17, 2004

Homosexuality is not genetic

In 1991, Simon LeVay studied the brains of nineteen cadavers that he believed were homosexual men, and sixteen cadavers that he believed were heterosexual men. (LeVay told Science magazine that he had “assumed“ the sexual orientation of some of his subjects.)

LeVay claimed to have found a group of neurons in the hypothalamus that appeared to be twice as large in the heterosexual men as the homosexual men. He then suggested that the size of this group of neurons, called the INAH3, might have something to do with sexual behavior. However, he never claimed to have found a genetic cause for homosexuality.

LeVay said, upon completing his work:

“It’s important to stress what I didn’t find. I did not prove that homosexuality is genetic, or find a genetic cause for being gay. I didn’t show that gay men are born that way, the most common mistake people make in interpreting my work.”

Some of LeVay’s peers noted that changes in brain structure could have been the result of homosexual behavior, rather than the cause. Dr. Kenneth Klivington stated:

“There is a body of evidence that shows the brain’s neural networks reconfigure themselves in response to certain experience. Therefore, the difference in homosexual brain structure may be a result of behavior and environmental conditions.”

Posted by Ted at February 17, 2004 8:39 PM