Gay activists frequently claim that homosexuals are born that way. For them, their sexual orientation is akin to something like eye color, inevitable and unchangeable, and therefore society must accept homosexuality as normal. Afterall, it is unfair to expect people to change their biologically influenced behavior.  

However, research attempting to show biological or genetic cause-and-effect for homosexuality dates back almost a century, and over the years, no research has ever proven a physical basis for homosexuality. The attempts were so persistent that homosexual activist Dennis Altman eventually admitted: “They are impressed with the considerable efforts of biologists, endocrinologists, and physiologists to prove this foundation; I am more impressed by the inability of many years of research to amount to no more than ‘suggestions'”. 

When neuroscientist Dr. Simon LeVay was at the Salk Institute, he studied a certain group of neurons in the hypothalamus structure of the brain (called INAH3 or interstitial nuclei of the anterior hypothalamus). He examined 41 cadavers, 19 of which were allegedly homosexual men, 16 of which were assumed to be heterosexual men, and six of which were assumed to be heterosexual women. Dr. LeVay found that some of the neurons in the hypothalamus region of the brain of heterosexual men were larger than those he found in homosexual men. He theorized that if homosexual men had smaller neurons, then possibly these smaller neurons were responsible for causing these men to be homosexual. Likewise, if heterosexual men had larger neurons, then possibly these larger neurons caused them to be heterosexual. LeVay assumed that if the size difference in neurons could be shown to be true 100 percent of the time, this would be evidence that homosexuality is biologically based.  

However, at least seven scientific reasons were put forth by critics who rejected his theory 

1. Dr. LeVay’s own chart, published in Science magazine, revealed there were flaws in his hypothesis. It even contradicts his theory. John Ankerberg had the privilege of interviewing Dr. LeVay at the Salk Institute in La Jolla, California, so we have his recorded comments on tape concerning this. Dr. Ankerberg said, “Look, you have three of the nuclei of the homosexual men which are actually larger than those of the heterosexual men. If your theory is valid, this should not be. Second, you have three of the heterosexual men with smaller nuclei than those of the homosexual men.” Ankerberg then asked, “Is that true?” And LeVay said, “Yes, that’s true.” So Dr. Ankerberg asked, “How could it be then, that the Associated Press reported that you ‘had always found that the nuclei were larger in the heterosexual men and smaller in homosexual men?’” Dr. LeVay admitted this was false. 

2. No scientist has ever proven that the particular region of the hypothalamus under discussion causes sexual orientation. Consider the comments of Dr. Joseph Nicolosi, who specializes in working with male homosexuals. His books “Healing Homosexuality: Case Stories of Reparative Therapy” and “Reparative Therapy of Male Homosexuality” gained him worldwide respect as an authority in same-sex attractions. Dr. Nicolosi emphasizes, “We’re talking about a general area of the brain that has to do with emotions, including sexuality; but in this particular nucleus, we have no clear understanding of what function it serves at this point.” So it would seem that 1) whether the neurons are large or small is not a firm indicator; and 2) no one really knows if they are even related to sexual orientation. 

3. Even if the anterior hypothalamus area of the brain could be shown to relate to sexual behavior, it still would not answer the question of cause and effect. In other words, what if homosexual behavior itself causes minute organic alterations in the body, which are only a posteriori assumed to be a contributing cause to homosexuality? Scientific studies have indicated that behavior itself might cause the size of the neurons to fluctuate, rather than the neurons causing specific homosexual or heterosexual behavior. Dr. Kenneth Klivington, former assistant to the president of the Salk Institute where Dr. LeVay did his study, pointed to “a body of evidence that shows the brain’s neural networks reconfigure themselves in response to certain experiences.” So the relationship between cause and effect—what affects what—is not clear. Therefore, the difference in homosexual brain structure—assuming further studies confirm LeVay’s “finding”—may be a result of certain behavior and/or environmental conditions. 

4. The sexual orientation of the people that Dr. LeVay studied could not be verified. When Dr. Ankerberg and Dr. LeVay discussed the fact that three heterosexual men had smaller nuclei than the homosexual men, LeVay said, “Well, maybe some of those individuals were bisexual.” Ankerberg responded, “But if it’s ‘maybe,’ then you don’t really know,” and indeed, Dr. LeVay confessed he really didn’t know. Some may even have been homosexuals “in the closet” who passed themselves off as heterosexuals. Because all the individuals studied were dead, we simply don’t know. 

5. The next problem with Dr. LeVay’s study involves the possibility of researcher bias. Dr. LeVay is openly gay and has publicly acknowledged this. He is also on record as stating that he set out to prove a genetic cause for homosexuality after his homosexual lover had died of AIDS. He was even quoted in an issue of Newsweek as asserting that if he did not find the genetic cause for homosexuality he sought, he would abandon science altogether. Newsweek further quoted him as saying he is seeking to “… [promote] the idea that homosexuality is a matter of destiny, not choice” because “it’s important to educate society” along the lines of biological influence. In fact, LeVay opened his own school for homosexuals and lesbians in Los Angeles to help get the message out. (Due to declining enrollment, LeVay’s Institute of Gay and Lesbian Education was closed in 1996.) In all fairness, isn’t it at least possible that a scientist with such a personal agenda might subject himself to researcher bias? 

6. The interpretation of data and methodology used by LeVay are also questionable. Other scientists have pointed out that the measurement Dr. LeVay used is suspect. Should the alleged influence of the nuclei be evaluated only by size—or, instead, by volume, actual cell count, density, or some other (or all three) criteria? Further, what do scientists do with each of these criteria? What does the data mean? The truth is that no one knows.  

7. LeVay’s study faces the problem of almost all research attempting to prove biological determinism: lack of replication. This seems to be the Achilles’ heel of all such endeavors, for it appears that almost invariably other scientists discover they are unable to replicate the findings of the initial study, which means that the initial study has proven nothing at all. No matter how widely the results are heralded as “scientific evidence,” the “evidence” is either found to be elusive or, if replicated, subject to other interpretations that undercut a biological theory. Concerning Dr. LeVay’s work, there is no replication of his findings in any other scientific study. In fact, at least one study by Dr. Schwab in The Netherlands flatly contradicts it.