Simon LeVay

Simon LeVay (born 28 August 1943 in Oxford, England) is a neuroscientist and author known for his studies about brain structures and sexual orientation. He is also the co-author of a textbook on human sexuality and has coauthored books on diverse topics such as earthquakes, volcanoes, and extraterrestrial life. ^[1]

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Education and career

• University of Cambridge, England (B.A., Natural Sciences, 1966)
• University of Göttingen, Germany (Ph.D., Neuroanatomy, 1971)
• Harvard Medical School (Postdoctoral Research Fellow, 1972-1974)

LeVay held positions at Harvard from 1974 to 1984, after which he worked at the Salk Institute from 1984-1993. While at the Salk institute he was also Adjunct Associate Professor of Biology at University of California, San Diego.

Much of his early work looked at visual cortex in animals, especially cats. LeVay's textbook on human sexuality (now in its second edition) was described in one review as "an exceptional book that addresses nearly every aspect of sexuality from multiple theoretical, historical, and cultural perspectives." ^[2]

Sexuality Research

LeVay's work and statements regarding biology and sexual orientation have been controversial. ^[3] In 1991 LeVay published an article suggesting a structural difference in the brains of homosexual and heterosexual men. This size difference was reported for the third interstitial nuclei of the anterior hypothalamus (INAH-3). ^[4] The finding was widely reported in the media. ^[5] The interstitial nuclei of the human anterior hypothalamus: an investigation of variation with sex, sexual orientation, and HIV status. ^[6]

LeVay has acknowledged that samples of gay men's brain tissue were readily available to him because they had died of AIDS-related illnesses. ^[7] Contemporaries of LeVay have questioned his measurements, noting the structures themselves are difficult to see in tissue slices, and LeVay measured in volume, where others state cell count is more accurate. ^[8] Nancy Ordover notes "he has also been criticized for his small sample size and for compiling inadequate sexual histories."^[9] Several of his colleagues have noted that the size of the nuclei could be impacted by AIDS, since INAH-3 is dependent on testosterone levels. ^[10] Hubbard and Wald note, "Though, on average, the size of the hypothalamic nucleus LeVay considered significant was indeed smaller in the men he identified as homosexual, his published data show that the range of sizes of the individual samples was virtually the same as for the heterosexual men. That is, the area was larger in some of the homosexuals than in many of the heterosexual men, and smaller in some of the heterosexual men than in many of the homosexuals. This means that, though the groups showed some difference as groups, there was no way to tell anything about an individual’s sexual orientation by looking at his hypothalamus." ^[11] Countering LeVay's claims suggesting homosexuality is a genetic predisposition (e.g. a "gay gene"), Brannon points out that "gender identity is a complex concept relating to feelings [...] that are not limited to or congruent with sexual behaviour." Brannon concludes that we simply do not know what this structure does or how it works in humans. ^[12] Byne noted "LeVay’s work has not been replicated, and human neuroanatomical studies of this kind have a very poor track record for reproducibility. Indeed, procedures similar to those LeVay used to identify nuclei have previously led researchers astray." ^[13] Biologist Joan Roughgarden notes that this is the tiniest of four "rice-grain" sized parts of the brain, and that sex and sexual orientation do not uniformly correspond to the hypothesis that "gay" brains are similar to "female" brains. ^[14]

None of the criticisms of LeVay's findings have adequately addressed all of the biological evidence published by researchers over the years, however. J. Michael Bailey, for instance, reported a 52% concordance rate for monozygotic twins' sexual orientation (compared to 22% for dizygotic twins)^[15], and Blanchard and Bogaert found an "Older Brother Effect," indicating a 1/3 increase in the likelihood that a man will be homosexual for every older brother he has. ^[16] Numerous studies have also shown the relative ease with which newborn rats' sexual orientation can be permanently altered via hormone treatment shortly after birth. ^[17]

Controversy

Criticism has also come from contemporaries, some of whom have questioned LeVay's measurements, noting the structures themselves are difficult to see in tissue slices, and LeVay measured in volume, where others state cell count is more accurate. ^[8] Nancy Ordover notes "he has also been criticized for his small sample size and for compiling inadequate sexual histories."^[9] Several of his colleagues have noted that the size of the nuclei could be impacted by AIDS, since INAH-3 is dependent on testosterone levels. ^[10]

It should be point out, however, that many of LeVay's critics have religious or other agendas that raise concerns. One of LeVay's most vocal critics, Dean Byrd, Ph.D, is a Conservative Mormon who speaks at LDS events about the success of so-called Conversion Therapies which purport to change sexual oriention through intensive religious counseling.^[18].

Ruth Hubbard (author of numerous articles and one book highly critical of explaining human behavior through genetics) and her son Elijah Wald noted in their co-authored book, "Though, on average, the size of the hypothalamic nucleus LeVay considered significant was indeed smaller in the men he identified as homosexual, his published data show that the range of sizes of the individual samples was virtually the same as for the heterosexual men. That is, the area was larger in some of the homosexuals than in many of the heterosexual men, and smaller in some of the heterosexual men than in many of the homosexuals. This means that, though the groups showed some difference as groups, there was no way to tell anything about an individual’s sexual orientation by looking at his hypothalamus." ^[11]

Byne noted "LeVay’s work has not been replicated, and human neuroanatomical studies of this kind have a very poor track record for reproducibility. Indeed, procedures similar to those LeVay used to identify nuclei have previously led researchers astray." ^[13] Biologist Joan Roughgarden notes that this is the tiniest of four "rice-grain" sized parts of the brain, and that sex and sexual orientation do not uniformly correspond to the hypothesis that "gay" brains are similar to "female" brains. ^[14]

LeVay cautions against misinterpreting his findings: "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. Nor did I locate a gay center in the brain." ^[19] He has also stated in a Newsweek interview "if I didn’t find anything, I would give up a scientific career altogether," ^[20] a comment critics claim is evidence of bias. ^[21]

LeVay has been criticized for advocating fetal screening for traits like homosexuality in order to abort fetuses with unwanted traits. A New York Times book review noted, "Indeed, he cheerfully looks forward to the day when the 'new eugenics' born of the human genome project will enable women to abort fetuses likely to be carrying any traits they don't much care for, including homosexuality." ^[22]

LeVay has posted on his website a response to the criticisms in this article--see External links below.

Selected bibliography

• LeVay S (1993). The Sexual Brain. Cambridge: MIT Press. ISBN 0-262-62093-6
• LeVay S (1996). Queer Science: The Use and Abuse of Research into Homosexuality. Cambridge: MIT Press. ISBN 0-262-62119-3
• LeVay S, Valente SM (Second ed., 2006). Human Sexuality. Sunderland: Sinauer Associates. ISBN ISBN 0-87893-465-0

References