There is a "debate" in America on the biological basis for homosexuality. The arguments from all sides are strongly opinionated, so where are the scientific facts?
The origins of the gay brain theory originated in 1991 with the study published by Simon LeVay, in which he studied the brain of homosexual and heterosexual men. He specifically targeted the hypothalamus—and even more specifically INAH—which is known to have an influence heterosexual sexual practices. If you can say it that way. LeVay claims to have found the INAH in homosexual men was twice the size of those in heterosexual men [1].
Criticism of LeVays work
LeVays work has not been replicated, and this already gives evidence for a flawed conclusion. Other studies set out to find the same correlation have failed to do so and always sided with traditionalists, in the sense that gays aren't "gay". Further note of all of the subjects in that study died of AIDS. AIDS decreases testosterone levels, meaning the difference in size might be because of the AIDS virus, not some gay gene or mutation. The homosexuals in that study did NOT have AIDS, meaning only the heterosexuals would be affected. So it makes sense homosexuals, according to his data, would have a larger hypothalamus. Now, the killer: LeVay did not even know if his subjects where gay! Brad Harrub, Ph.D. and Bert Thompson, Ph.D. and Dave Miller, Ph.D. note, "Furthermore, in a scientific environment where controls and standards are a necessity, LeVay did not possess a complete medical history of the individuals included in his study. He therefore was forced to assume the sexual orientation of the non-AIDS victims as being heterosexual, when some may not have been."[2] What is interesting, however, is that LeVay now agrees that conversion therapy might be effective, a big flip flop isn't it [3]?
What science says
Science leads to the conclusion anyone could have guessed, being gay is not caused by the brain differences! Brain differences actually support environmental theory, that environmental factors play a role in homosexual orientation. Interestingly enough, when born, male and female brains are identical. Note, this does not mean being heterosexual is unnatural, as genes don't always affect the brain (so this post =/= death to gay gene theory, I will deal with those theories later, but it ends the hypothalamus cause). Neil and Briar Whitehead note,
In another post, I will examine twin evidence and Hamers study. As finding the exact gene (as Hamer tried to do) or twin studies are the only ways to determine the born gay phenomena.
1. LeVay, Simon, “A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men,” Science, (1991).
2. Harrub, Brad, Ph.D., Bert Thompson, Ph.D., and Dave Miller, Ph.D. "Science vs. the "Gay Gene"" Science vs. the "Gay Gene" True Origin, 2003. Web. 04 Oct. 2012. <http://www.trueorigin.org/gaygene01.asp>.
3. Nicolosi, Linda A. "Some Gay Advocates Acknowledge Reorientation Therapy as a Legitimate Option--Simon LeVay Joins Douglas Haldeman in Qualified Support." Some Gay Advocates Acknowledge Reorientation Therapy as a Legitimate Option--Simon LeVay Joins Douglas Haldeman in Qualified Support. National Association for Research & Therapy of Homosexuality, n.d. Web. 04 Oct. 2012. <http://narth.com/docs/legitimate.html>.
4. Whitehead, Neil, Ph.D., and Briar Whitehead, B.A. My Genes Made Me Do It!: [a Scientific Look at Sexual Orientation]. Lafayette, LA: Huntington House, 2010
The origins of the gay brain theory originated in 1991 with the study published by Simon LeVay, in which he studied the brain of homosexual and heterosexual men. He specifically targeted the hypothalamus—and even more specifically INAH—which is known to have an influence heterosexual sexual practices. If you can say it that way. LeVay claims to have found the INAH in homosexual men was twice the size of those in heterosexual men [1].
Criticism of LeVays work
LeVays work has not been replicated, and this already gives evidence for a flawed conclusion. Other studies set out to find the same correlation have failed to do so and always sided with traditionalists, in the sense that gays aren't "gay". Further note of all of the subjects in that study died of AIDS. AIDS decreases testosterone levels, meaning the difference in size might be because of the AIDS virus, not some gay gene or mutation. The homosexuals in that study did NOT have AIDS, meaning only the heterosexuals would be affected. So it makes sense homosexuals, according to his data, would have a larger hypothalamus. Now, the killer: LeVay did not even know if his subjects where gay! Brad Harrub, Ph.D. and Bert Thompson, Ph.D. and Dave Miller, Ph.D. note, "Furthermore, in a scientific environment where controls and standards are a necessity, LeVay did not possess a complete medical history of the individuals included in his study. He therefore was forced to assume the sexual orientation of the non-AIDS victims as being heterosexual, when some may not have been."[2] What is interesting, however, is that LeVay now agrees that conversion therapy might be effective, a big flip flop isn't it [3]?
What science says
Science leads to the conclusion anyone could have guessed, being gay is not caused by the brain differences! Brain differences actually support environmental theory, that environmental factors play a role in homosexual orientation. Interestingly enough, when born, male and female brains are identical. Note, this does not mean being heterosexual is unnatural, as genes don't always affect the brain (so this post =/= death to gay gene theory, I will deal with those theories later, but it ends the hypothalamus cause). Neil and Briar Whitehead note,
There is remarkably little evidence of differences between boys and girls at birth. ... If only about one quarter of the neurons in the adult brain are present at birth, and the form and structure of the remaining 75% that develop, depend heavily on learning, experience, exercise and behaviour, then there are grounds for arguing that about one quarter of brain structure is biologically fixed and three quarters is the result of environmental interaction. ... If only about one quarter of the neurons in the adult brain are present at birth, and the form and structure of the remaining 75% that develop, depend heavily on learning, experience, exercise and behavior, then there are grounds for arguing that about one quarter of brain structure is biologically fixed and three quarters is the result of environmental interaction [4].In other words, brains have no role in overall sexual orientation, and have no role in homosexual orientation. So, when looking into if a gene causes homosexuality (or heterosexuality), we must go into Hamers study and twin studies. So, if someone cites LeVay, its easy to shoot them down. The hypothalmus does not affect orientation (though does affect testosterone levels, but Whitehead notes that always changes). So no permenant preference via the brain exists.
In another post, I will examine twin evidence and Hamers study. As finding the exact gene (as Hamer tried to do) or twin studies are the only ways to determine the born gay phenomena.
1. LeVay, Simon, “A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men,” Science, (1991).
2. Harrub, Brad, Ph.D., Bert Thompson, Ph.D., and Dave Miller, Ph.D. "Science vs. the "Gay Gene"" Science vs. the "Gay Gene" True Origin, 2003. Web. 04 Oct. 2012. <http://www.trueorigin.org/gaygene01.asp>.
3. Nicolosi, Linda A. "Some Gay Advocates Acknowledge Reorientation Therapy as a Legitimate Option--Simon LeVay Joins Douglas Haldeman in Qualified Support." Some Gay Advocates Acknowledge Reorientation Therapy as a Legitimate Option--Simon LeVay Joins Douglas Haldeman in Qualified Support. National Association for Research & Therapy of Homosexuality, n.d. Web. 04 Oct. 2012. <http://narth.com/docs/legitimate.html>.
4. Whitehead, Neil, Ph.D., and Briar Whitehead, B.A. My Genes Made Me Do It!: [a Scientific Look at Sexual Orientation]. Lafayette, LA: Huntington House, 2010
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