UPDATED 09/24/19

An article in Science discusses the findings of a recent “genome-wide association study (GWAS) [by Andrea Ganna et al.], in which the genome is analyzed for statistically significant associations between single-nucleotide polymorphisms (SNPs) and a particular trait.” That upshot is that

genetics could eventually account for an upper limit of 8 to 25% of same-sex sexual behavior of the population. However, when all of the SNPs they identified from the GWAS are considered together in a combined score, they explain less than 1%. Thus, although they did find particular genetic loci associated with same-sex behavior, when they combine the effects of these loci together into one comprehensive score, the effects are so small (under 1%) that this genetic score cannot in any way be used to predict same-sex sexual behavior of an individual.

Further, “Ganna et al. did not find evidence of any specific cells and tissues related to the loci they identified.”

Is this a big change from what was thought previously about genes and homosexuality? Yes, according to an article in ScienceNews:

The new study is an advance over previous attempts to find “gay genes,” says J. Michael Bailey, a psychologist at Northwestern University in Evanston, Ill., who was not involved in the new work. The study’s size is its main advantage, Bailey says. “It’s huge. Huge.”…

Previous sexual orientation genetic studies, including some Bailey was involved in, may also have suffered from bias because they relied on volunteers. People who offer to participate in a study, without being randomly selected, may not reflect the general population, he says. This study includes both men and women and doesn’t rely on twins, as many previous studies have….

This is the first DNA difference ever linked to female sexual orientation, says Lisa Diamond, a psychologist at the University of Utah in Salt Lake City who studies the nature and development of same-sex sexuality. The results are consistent with previous studies suggesting genetics may play a bigger role in influencing male sexuality than female sexuality. It’s not unusual for one sex of a species to be more fluid in their sexuality, choosing partners of both sexes, Diamond says. For humans, male sexuality may be more [but not very] tightly linked to genes.

But that doesn’t mean that genes control sexual behavior or orientation. “Same-sex sexuality appears to be genetically influenced, but not genetically determined,” Diamond says. “This is not the only complex human phenomenon for which we see a genetic influence without a great understanding of how that influence works.” Other complex human behaviors, such as smoking, alcohol use, personality and even job satisfaction all have some genetic component [emphasis added].

In sum, as an article in The Telegraph about the Ganna study explains,

[g]enes play just a small role in whether a person is gay, scientists have found, after discovering that environment has a far bigger impact on homosexuality….

[G]enes are responsible for between eight to 25 per cent of the probability of a person being gay, meaning at least three quarters is down to environment.

What’s most interesting about the commentary that I’ve read, including portions of the articles just quoted above, is what “environment” means to those who are eager to preserve the illusion of homosexuality as a condition that’s almost unavoidable.

The article in The Telegraph quotes one of the Ganna study’s authors, who is hardly a disinterested party:

As a gay man I’ve experienced homophobia and I’ve felt both hurt and isolated by it. This study disproves the notion there is a so-called ‘gay gene’ and disproves sexual behaviour is a choice.

Genetics absolutely plays an important role, many genes are involved, and altogether they capture perhaps a quarter of same-sex sexual behaviour, which means genetics isn’t even half the story. The rest is likely environmental.

It’s both biology and environment working together in incredibly complicated ways.

How does the study disprove that sexual behavior is a choice? It does so only if one makes the valiant assumption that environmental influences somehow don’t operate on behavior, and aren’t in turn shaped by behavior.

Another scientist, quoted in The Telegraph article, acknowledges my point:

There is an unexplained environmental effect that one can never put a finger on exactly it’s such a complex interplay between environment, upbringing, and genetics [emphasis added].

The Associated Press, always ready to spin news leftward, ran a story with the same facts and interpretations as those quoted earlier, but with the headline: “Study finds new genetic links to same-sex sexuality”. Which hides  the gist of the story: Homosexuality is mainly determined by environmental influences, which include and are shaped by behavioral choices.

What’s left unmentioned, of course, is that homosexuality is therefore predominantly a choice. What’s also left unmentioned are the environmental influences that are most likely to induce homosexual behavior. Here is my not-mutually-exclusive list of such influences:

• shyness toward the opposite sex (caused by introversion, fear of rejection, self-assessment as unattractive)
• proximity of potential sexual partners who are shy toward the opposite sex and/or open to experimentation, or who are seeking opportunities to seduce those who are shy and/or experimental
• conditions conducive to experimentation (sleepovers, drunkenness, pornographic titillation)
• encouraging or permissive milieu (parental encouragement/indifference, parental absence — as when a person is away at college, especially a “liberal” college populated by sexual experimenters/homosexuals)
• general indifference or approbation (secularization of society, removal of criminal sanctions, legalization of sodomy, legalization of same-sex marriage, elite embrace and praise of non-traditional sexual behavior and roles: bisexuality, homosexuality, transgenderism).

All of those influences operate on the urge for sexual satisfaction, which is especially strong in adolescents and young adults. Given that urge, the incidence of introversion, the incidence of physical unattractiveness, the unconscionably large number of persons in college, and the social and legal trends of recent decades, it is almost shocking to learn that only about five percent of American adults think of themselves as LGBT. If you live in a “cosmopolitan” city of any size, you might believe that they account for a much larger fraction of the population. But that’s just due to the clustering effect — birds of a feather, and all that. Even if you don’t live in a “cosmopolitan” city, you may believe that far more than five percent of the population is LGBT because the producers of films and TV fare — “cosmopolitan” elites that they are — like to “celebrate diversity”. (Or, more aptly, shove it down your throat.)

In summary, I submit that most persons of the LGBT persuasion make a deliberate and often tragic choice about their “sexual identity”. (See, for example, my post, “The Transgender Fad and Its Consequences“, and Carlos D. Flores’s article, “The Absurdity of Transgenderism: A Stern But Necessary Critique“.)

I submit, further, that the study by Ganna et al. implies that conversion therapy could be effective, and that (politically correct) “scientific” opposition to it is based on the now-discredited view of homosexuality as a genetically immutable condition.

If the apologists for and promoters of LGBT “culture” were logically consistent in their insistence on homosexuality as a genetic condition, they would also acknowledge that intelligence is largely a matter of genetic inheritance. They don’t do that, generally, because they are usually leftists who subscribe to the blank-slate view of inherent equality.

If any trait is strongly genetic in origin, it is the abhorrence of homosexuality, which is a threat to the survival of the species.

UPDATE

There is some support for my hypothesis about environmental causes of homosexual behavior in Gregory Cochran’s post, “Gay Genes” at West Hunter, where he discusses the paper by Ganna et al.:

They found two SNPs [single-nucleotide polymorhpisms] that influenced both male and female homosexuality, two that affected males only, one that affected females only. All had very small but statistically significant effects….

The fraction of the variance influenced by these few SNPs is low, less than 1%. The contribution of all common SNPs is larger, estimated to be between 8% and 25%. Still small compared to traits like height and IQ, but then we knew that the heritability of homosexuality is not terribly high, from twin studies and such – political views are more heritable.

So genes influence homosexuality, but then they influence everything. Does it look as if the key causal link (assuming that there is one) is genetic? No, but then we knew that already, from high discordance for homosexuality in MZ twins.

Most interesting to me were the genetic correlations between same-sex behavior and various other traits [displayed in a graph]….

The genes correlated with male homosexuality are also correlated ( at a statistically significant level) with risk-taking, cannabis use,  schizophrenia, ADHD, major depressive disorder, loneliness, and number of sex partners. For female homosexuals, risk-taking, smoking, cannabis use, subjective well-being (-), schizophrenia, bipolar disorder, ADHD, major depressive disorder, loneliness, openness to experience, and number of sex partners.

Generally, the traits genetically correlated with homosexuality are bad things.  As far as I can see,  they look like noise, rather than any kind of genetic strategy.  Mostly, they accord with what we already knew about male and female homosexuals: both are significantly more likely to have psychiatric disorders, far more likely to use drugs.   The mental-illness association maybe looks stronger in lesbians.  The moderately-shared genetic architecture seems compatible with a noise model….

[The finding] that homosexuality was genetically correlated with various kinds of unpleasantness was apparently an issue in the preparation and publication of this paper. The authors were at some pains  to avoid hurting the feelings of the gay community, since avoiding hurting  feelings is the royal road to Truth, as shown by Galileo and Darwin.

If there are genes for bad behavior, it is the penchant for bad behavior that pushes some persons in the direction of homosexuality. But the choice is theirs. Many persons who are prone to bad behavior become serial philanderers, serial killers, sleazy politicians, etc., etc., etc. Homosexuality isn’t a necessary outcome of bad behavior, just a choice that many persons happen to make because of their particular circumstances.

P.S. I don’t mean to imply that bad behavior and homosexuality go hand-in-hand. As I suggest in the original post, there are other reasons for choosing homosexuality in those cases (the majority of them) where it isn’t a genetic predisposition.

(See also “The Myth That Same-Sex Marriage Causes No Harm“, “Two-Percent Tyranny“, and “Further Thoughts about Utilitarianism“.)