The Born Gay Theory
The ‘born gay’ theory really began to be embraced during the early 1990s as a result of the findings by three scientists alleging genetic and biological influences of sexual orientation. Each of the studies gained great headlines by suggesting homosexuality was possibly inborn - suggesting people are born gay. Details about the work of these scientists is provided in other articles.
At about the same time, in 1990, an international, collaborative research project set out to map and understand human genes. All our genes together are known as our “genome”. The research program was named the Human Genome Project and was funded by the U.S. Department of Energy and the National Institutes of Health.
In 1999, after nearly ten years of systematic learning by the Human Genome Project, Canadian scientists at the Department of Clinical Neurological Sciences of the University of Western Ontario attempted to confirm if earlier theories of a genetic basis for sexual orientation were correct. Up until that point no one had tried to duplicate the 1993 report by Dr. Hamer of the National Cancer Institute in Bethesda, Maryland or other similar reports from the 1990's. Dr. Hamer had hypothesized that since there are a great number of homosexual uncles and cousins on the mother’s side that the mother was the one who carried the genetic markers of homosexuality on the X chromosome that she passed down to her children. He analyzed the DNA of forty families that produced two gay sons and concluded that 80% of the time the gay brothers shared certain genetic markers on the q28 region on the arm of the X chromosome. Dr. Hamer was hopeful that the Human Genome Project was going to discover many genetic links to human sexual behavior. [i] One significant problem with Dr. Hamer’s study, though, was his failure to check whether the heterosexual brothers from those families shared the markers in question.[ii]
The Canadian scientists came to a different conclusion than Dr. Hamer. The Ontario Team concluded, "...our study was larger than that of Hamer et al" and "...found no evidence of linkage of sexual orientation to Xq28."[iii] They disproved the validity of this earlier theory about a “gay gene.”
In 2003, the Human Genome Project finished. Since then a genetic predisposition to homosexuality has not been found despite the fact that we know so much about the genome. So in other words, if a scientist pulled ten random people out of a crowd and examined their DNA, scientists would not be able to identify who was homosexual. The only way that one would know who was gay or not was if the people revealed their feelings or their sexual history. The use of scientific inquiry is inadequate at identifying homosexual people.
When all of the work being done on the causes of sex orientation is put together, the question about what causes sexual orientation seems best answered as follows.
First, science does not have a firm answer that everyone in the field of science, let alone everyone else, can agree on. The origins of sexual orientation are still not clearly understood by scientists.
Second, most researchers agree that the causes of same-sex attractions are multi-causal and complex; many factors contribute to the development of same-sex attraction. Most researchers, including Dr. Dean Hamer, the "gay gene” researcher who is himself a gay man, agree that same-sex attractions are due to a combination of social, biological, and psychological factors. Dr. Hamer has said, "Genes are hardware…the data of life’s experiences are processed through the sexual software into the circuits of identity. I suspect the sexual software is a mixture of both genes and environment, in much the same way the software of a computer is a mixture of what’s installed at the factory and what’s added by the user [P. Copeland and D. Hammer, The Science of Desire, New York: Simon and Schuster, 1994]”
Third, the combination of factors is different for each person.
So, returning to the question - are people born gay? The answer is no. The causes of sexual orientation are multi-causal and complex, and we should not adopt a simplistic approach when looking for what causes sexual orientation.
References
[i] Dean H. Hamer et al., “A Linkage Between DNA Markers on the X Chromosome and Male Sexual Orientation,” Science 16 July 1993: 321-326.
[ii] Brad Harrub, et al., “This Is the Way God Made Me.” 2003. Apologetics Press, Inc. 13 September 2004 http://trueorigin.org/gaygene01.asp
[iii] George Rice et al., “Male Homosexuality: Absence of Linkage to Microsatellite Markers at Xq28,” Science 23 April 1999: 665-667.