Sexual orientation can’t be explained by genetics alone

| | November 19, 2014

Just recently, the largest twin study to date examining genes’ influence on homosexuality was published in the journal Psychological Medicine. The study involved 409 pairs of homosexual brothers. Genome-wide analyses showed strong evidence, the researchers claimed, that two chromosomes, X and chromosome 8, mediated homosexuality based on the genes they shared.

For some experts, particularly those involved with the work, the findings had “landmark” written all over them. But for those less optimistic, the study was flimsy and statistically mediocre, if outright insignificant. Even Dr. Alan Sanders, a behavioral genetics researcher at NorthShore University HealthSystem Research Institute and the study’s lead author, said the evidence “is not proof, but it’s a pretty good indication” that genes wield some influence on sexuality.

Clearly, the controversy exists. For as long as scientists have had access to people’s genes, they’ve tested the idea that who we’re attracted to is written into our DNA — some so-called “gay gene” exists, and if only we look hard enough we will find it. But this raises startling questions about which scientific findings matter the most to us, particularly as our knowledge of the brain grows in parallel to our known ignorance of its power.

The brain isn’t a painting that scientists can walk around in. It’s a hurricane, where things are constantly swirling in flux. And sexuality, for that matter, is just as turbulent. The terms we use to describe certain urges — “gay,” “straight,” or some other shade of gray in between — don’t exist in nature. We made them up. According to Brian Earp, of the University of Oxford Uehiro Centre for Practical Ethics, the best science can do to trace sexuality’s origins is get kind of close.

“It can say, ‘Given this sort of genetic information it turns out that this leads to this sort of probability that the person will consciously express these kinds of sexual attractions,” Earp told Medical Daily.

Read full, original article: The Red Herring ‘Gay Gene,’ And How Sexuality Is More Than Just Genetics

The GLP aggregated and excerpted this article to reflect the diversity of news, opinion, and analysis. Click the link above to read the full, original article.

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