Study: Same-sex Sexuality a mixture of genetics, social/environmental factors

[TitanTiger 20,472]

 

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Many Genes Influence Same-Sex Sexuality, Not a Single ‘Gay Gene’

The largest study of same-sex sexual behavior finds the genetics are complicated, and social and environmental factors are also key.

By Pam Belluck

Aug. 29, 2019

How do genes influence our sexuality? The question has long been fraught with controversy.

An ambitious new study — the largest ever to analyze the genetics of same-sex sexual behavior — found that genetics does play a role, responsible for perhaps a third of the influence on whether someone has same-sex sex. The influence comes not from one gene but many, each with a tiny effect — and the rest of the explanation includes social or environmental factors — making it impossible to use genes to predict someone’s sexuality. 

“I hope that the science can be used to educate people a little bit more about how natural and normal same-sex behavior is,” said Benjamin Neale, a geneticist at the Broad Institute of M.I.T. and Harvard and one of the lead researchers on the international team. “It’s written into our genes and it’s part of our environment. This is part of our species and it’s part of who we are.”

The study of nearly half a million people, funded by the National Institutes of Health and other agencies, found differences in the genetic details of same-sex behavior in men and women. The research also suggests the genetics of same-sex sexual behavior shares some correlation with genes involved in some mental health issues and personality traits — although the authors said that overlap could simply reflect the stress of enduring societal prejudice. 

Even before its publication Thursday in the journal Science, the study has generated debate and concern, including within the renowned Broad Institute itself. Several scientists who are part of the L.G.B.T.Q. community there said they were worried the findings could give ammunition to people who seek to use science to bolster biases and discrimination against gay people.

One concern is that evidence that genes influence same-sex behavior could cause anti-gay activists to call for gene editing or embryo selection, even if that would be technically impossible. Another fear is that evidence that genes play only a partial role could embolden people who insist being gay is a choice and who advocate tactics like conversion therapy.

“I deeply disagree about publishing this,” said Steven Reilly, a geneticist and postdoctoral researcher who is on the steering committee of the institute’s L.G.B.T.Q. affinity group, Out@Broad. “It seems like something that could easily be misconstrued,” he said, adding, “In a world without any discrimination, understanding human behavior is a noble goal, but we don’t live in that world.”

Discussions between Dr. Neale’s team and colleagues who questioned the research continued for months. Dr. Neale said the team, which included psychologists and sociologists, used suggestions from those colleagues and outside L.G.B.T.Q. groups to clarify wording and highlight caveats.

“I definitely heard from people who were kind of ‘why do this at all,’ and so there was some resistance there,” said Dr. Neale, who is gay. “Personally, I’m still concerned that it’s going to be deliberately misused to advance agendas of hate, but I do believe that the sort of proactive way we’ve approached this and a lot of the community engagement aspects that we’ve tried were important.”

The moment the study was published online Thursday afternoon, the Broad Institute took the unusual step of posting essays by Dr. Reilly and others who raised questions about the ethics, science and social implications of the project.

“As a queer person and a geneticist, I struggle to understand the motivations behind a genome-wide association study for non-heterosexual behavior,” wrote Joe Vitti, a postdoctoral researcher at the Broad Institute, in one essay. “I have yet to see a compelling argument that the potential benefits of this study outweigh its potential harms.”

In a way, the range of opinions by scientists who also identify as L.G.B.T.Q. underscores a central finding of the study: Sexuality is complicated.

The study analyzed the genetic data of 408,000 men and women from a large British database, the U.K. Biobank, who answered extensive health and behavior questions between 2006 and 2010, when they were between the ages of 40 and 69. The researchers also used data from nearly 70,000 customers of the genetic testing service 23andMe, who were 51 years old on average, mostly American, and had answered survey questions about sexual orientation. All were of white European descent, one of several factors that the authors note limit their study’s generalizability. Trans people were not included.

The researchers mainly focused on answers to one question: whether someone ever had sex with a same-sex partner, even once.

A much higher proportion of the 23andMe sample — about 19 percent compared to about 3 percent of the Biobank sample — reported a same-sex sexual experience, a difference possibly related to cultural factors or because the specific 23andMe sexual orientation survey might attract more L.G.B.T.Q. participants.

Despite its limitations, the research was much larger and more varied than previous studies, which generally focused on gay men, often those who were twins or were otherwise related.

“Just the fact that they look at women is hooray,” said Melinda Mills, a professor of sociology at the University of Oxford, who wrote a commentary that Science published alongside the study.

There might be thousands of genes influencing same-sex sexual behavior, each playing a small role, scientists believe. The new study found that all genetic effects likely account for about 32 percent of whether someone will have same-sex sex. 

Using a big-data technique called genome-wide association, the researchers estimated that common genetic variants — single-letter differences in DNA sequences — account for between 8 percent and 25 percent of same-sex sexual behavior. The rest of the 32 percent might involve genetic effects they could not measure, they said. 

Researchers specifically identified five genetic variants present in people’s full genomes that appear to be involved. Those five comprise less than 1 percent of the genetic influences, they said.

And when the scientists tried to use genetic markers to predict how people in unrelated data sets reported their sexual behavior, it turned out to be too little genetic information to allow such prediction. 

“Because we expect the sum of the effects that we observe will vary as a function of society and over time, it will be basically impossible to predict one’s sexual activity or orientation just from genetics,” said Andrea Ganna, the study’s first author, whose affiliations include the Institute of Molecular Medicine in Finland.

While many genetic variants tend to have the same effect in both men and women, Dr. Mills said, two of the five variants the team found were discovered only in males and one was discovered only in females. One of the male variants might be related to sense of smell, which is involved in sexual attraction, the researchers report. The other male variant is associated with male pattern balding and sits near genes involved in male sex determination.

In a finding that could be especially sensitive, the researchers found that whether someone ever engaged in same-sex sexual behavior showed genetic correlations with mental health issues, like major depressive disorder or schizophrenia, and with traits like risk-taking, cannabis use, openness to experience and loneliness.

They emphasized that the study does not suggest that same-sex sexual behavior causes or is caused by these conditions or characteristics, and that depression or bipolar disorder could be fueled by prejudicial social experiences. 

“We are particularly worried that people will misrepresent our findings about mental health,” Dr. Neale said.

“That right there is the big issue with looking for the genetics of sexual orientation — social context could be a big part of the expression of the trait,” said Jeremy Yoder, an assistant professor of biology at California State University, Northridge, who is gay and follows genetic research in the field. 

Dr. Neale said younger study participants were much more likely than older ones to report same-sex sexual experiences, possibly reflecting increased social acceptance. He and others noted that older participants came of age when homosexual behavior was criminalized in Britain and that for much of their life homosexuality was classified as a psychiatric disorder.

Dr. Reilly and others said such stark differences between older and younger participants show the trickiness of trying to draw representative biological information from a study population so strongly influenced by society’s changing attitudes. People steeped in a culture that demonized same-sex intimacy might only have the gumption to reveal it in a study if they were risk-takers to begin with.

Later, the researchers compared the genetic underpinnings of whether people ever had same-sex sex with their answers to what proportion of same-sex partners they had. They found there was little genetic correlation between answers to the “ever-never” question and whether someone ended up having a bisexual mix of partners, said Dr. Neale, who sees those results as a genetic reflection of the variety of sexual orientations within the expanding alphabet of the L.G.B.T.Q. community. 

The researchers also looked at answers to other questions in the 23andMe survey, including people’s sexual identity and what gender they fantasized about. There, they found considerable genetic overlap between those results and whether people ever engaged in same-sex sex, suggesting that these aspects of sexual orientation share common genetics, they said. 

Dean Hamer, a former National Institutes of Health scientist who led the first high-profile study identifying a genetic link to being gay in 1993, said he was happy to see such a large research effort.

“Having said that, I’d like to emphasize that it’s not a gay gene study — it’s a study of what makes people have a single same-sex experience or more,” said Dr. Hamer, now an author and filmmaker. The gene he identified was on the X chromosome, one of the sex chromosomes, a location the new study did not flag as being significant for same-sex sexual behavior.

“Of course they didn’t find a gay gene — they weren’t looking for one,” Dr. Hamer said. 

Experts widely agree that the research was conducted by first-rate scientists.

“I kind of held my breath when I first saw the study — I thought, oh no,” said Dr. Mills of Oxford. “But it’s the top geneticists and some of the top social scientists in the field working on this, so if somebody was going to do it, I’m glad they did it.”

Indeed, Dr. Neale, who also consults for several pharmaceutical companies, said one reason his team did the study was to ensure less careful researchers would not tackle it first, “given how sensitive and hot-button this topic really is and how personal it is.”

Robbee Wedow, a member of the research team who also belongs to Out@Broad, served as a kind of bridge, organizing meetings between the researchers and their Broad Institute critics. 

“I grew up in a highly religious evangelical family,” said Dr. Wedow, a research fellow with the Broad Institute and Harvard’s sociology department. “Being confused about not being attracted to women and being attracted to men, being convinced it was a sin and that I would go to hell.”

For a long time, “I definitely tried to pray it away, tried to like girls, tried to have girlfriends,” he said. “This wasn’t something I, of all people, would have chosen. There must be some sort of biological background.”

He concluded: “Saying ‘sorry, you can’t study this’ reinforces it as something that should be stigmatized.”

Outside L.G.B.T.Q. groups that were consulted did not seem as strongly concerned as some of the Out@Broad members, he said. Zeke Stokes, chief programs officer at GLAAD, who was shown the findings several months ago, said, “Anyone who’s L.G.B.T.Q. knows that their identity is complicated and to have science sort of bear that out is a positive thing.”

Over all, Dr. Neale said he believes the study shows that “diversity is a natural part of our experience and it’s a natural part of what we see in the genetics. I find that to actually just be beautiful.”

[Like the Science Times page on Facebook. | Sign up for the Science Times newsletter.]

https://www.nytimes.com/2019/08/29/science/gay-gene-sex.html

 

I have a couple of thoughts on this.  First was this part:

“I deeply disagree about publishing this,” said Steven Reilly, a geneticist and postdoctoral researcher who is on the steering committee of the institute’s L.G.B.T.Q. affinity group, Out@Broad. “It seems like something that could easily be misconstrued,” he said, adding, “In a world without any discrimination, understanding human behavior is a noble goal, but we don’t live in that world.” 

Am I reading this right, because it reads to me like "don't tell us the truth because it might be misused."  In other words, "let us craft whatever narrative about this subject we want and don't question it."

Second, I found it odd that they connected genetics and same-sex sex.  And I wasn't the only one who picked up on that.  A Twitter thread:

 

Tish Harrison Warren

@Tish_H_Warren

33 minutes ago, 11 tweets, 2 min read  Read on Twitter

This is completely fascinating. And oooh boy is it a lot to think about.
 

Many Genes Influence Same-Sex Sexuality, Not a Single ‘Gay Gene’The largest study of same-sex sexual behavior finds the genetics are complicated, and social and environmental factors are also key.https://www.nytimes.com/2019/08/29/science/gay-gene-sex.html

Some initial thoughts:
1. The take away is that sexuality & sexual orientation is massively complex. This seems self-evident but is not often the way it's popularly talked about.
 

2. A Christian anthropology & sexual ethic supports this idea. All of our sexualities & orientations (whether gay, straight, asexual, or somewhere in between) are as myriad and diverse as our individual stories. So complex that only God fully understands them or how we got here.
 

3. This also means that all of us--gay and straight--are affected by God's image and glory *in our sexuality.* And that all of us--gay and straight--are affected by the Fall in our sexuality.
 

4. When gay people claim their sexuality/sexual expression isn't fallen, that's not a Christian claim. And when straight people-often by virtue of being straight-claim their sexuality/sexual expression isn't fallen, that isn't a Christian claim.
 

5. All sexuality bears marks of grace & marks of sin. We have to allow for this deep complexity in our conversation as a church. We all begin as image bearers and we all are wrecked and cracked to the core. No one gets to claim utter sexual wholeness. We start in need of grace.
 

6. Okay, so all that said (preachers gone preach...). I don't love the language of genetics plays a role in "whether someone has same-sex sex." It seems like genetic determinism. Can totally buy that it plays a role in attraction/orientation/desires.
 

7. But it seems genetics doesn't determine who we sleep with. Any more than genetics determines if I eat the cake in my fridge (though I have diabetes & it would harm me...and I'm genetically predisposed to like sweets).
 

8. If I could wave a wand and permanently kill the "choice" v. "genes" debate, I would. No sane person thinks being gay is something someone wholesale wakes up and chooses one day. But that is never the point --or the view--of Christians understanding of sexuality, ethics, or sin
 

9. All that to say, the main point of this article is that ssa is not mainly or mostly genetically. It's mostly determined by environmental factors. But what I . now what to know is: what factors? Early sexual experiences, family, community, societal norms, what? I'd love to know
 

10. Lastly, it’s fascinating to me that this is an article about science but 90% is a debate about ethics & ideology. All for science but it’s obvious science is never merely objective. Science is full of presuppositions, faith, & metaphysics.
 

Also sorry about the typos...I wrote this too quickly for my own good.

 

https://twitter.com/Tish_H_Warren/status/1167512319091499010

 

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All that said, thoughts?  What are the implications of the study that come to mind for you?  And is the idea that genetics leads to certain behaviors a sort of "genetic determinism" as Tish Warren says in her tweet thread?

 

I think for me I tend to agree with her - I think the genetics factors (as well as social/environmental ones) can tell us why someone may be predisposed to certain desires/feelings/attractions but not behaviors.  And like her, I'd love to know what social or environmental factors they found or believe play a role and how much each of those factors play that role?

 

Also, in identifying these genes, what are the implications of finding a gene like this for parents being able to do genetic selection or even gene therapy to minimize or eliminate the likelihood or their child being gay?

 

The study seems to raise far more questions than it answers. 

[homersapien 11,366]

1 hour ago, TitanTiger said:

 

The study seems to raise far more questions than it answers. 

Which is quite typical of most scientific research.

I don't find any of this particularly surprising.

[DKW 86 7,419]

I have always considered it to be an all inclusive thing. Even genetics isnt a 100% thing. The wrong genes TEND to get you cancer, diabetes, high blood pressure, etc. But they are never 1:1 correlated. Sexuality is always  a mix of culture, past experiences, upbringing, and disposition, etc. I learned a long time ago that the best sex organ we have is between the ears. Your brian chemistry etc can make you plaine vanilla missionary sex only for kids or a Wilt Chamberlain, or a Jeffrey Epstein.  

I personally dont care. As long as two people are happy and in a loving non-abusive realtionship, I couldnt care less.
As the song says "Sodomy is between God and me..."

 

[alexava 6,973]

I know what I know. Two of my very best friends are about 35 years together/ married one is more like a brother came up in the 60-70s. The youngest of 7 kids 5 boys, on a dairy farm. Raised church of Christ. Knew from a very young age he was gay and fought it with everything he had till he was 27 years old. Then realized he had to love himself and who he was or quit living at all. My friend is as genuine as you can be. He goes to an accepting church. He was never abused or influenced by other factors his brothers weren’t. He can attest that he had zero choice in the matter. The last thing I want for my friend is people trying to tell him he’s weak, deranged, flawed or could have been rescued from the good life he is living right now if he “just wanted to be “. I’m all about research but I don’t really need results of a study to inform me that this man was born to be who he is. His friendship has has made a positive difference in my life and my family and many others. If he had taken a different fork in the road at 27 the world wouldn’t be a bette place. 

I am less familiar but aware of others who may have been influenced by being raised around all women and ended up gay. I don’t think you can fix them either but would be interested in seeing a study about that as well. 

[kevon67 2,368]

9 minutes ago, alexava said:

I know what I know. Two of my very best friends are about 35 years together/ married one is more like a brother came up in the 60-70s. The youngest of 7 kids 5 boys, on a dairy farm. Raised church of Christ. Knew from a very young age he was gay and fought it with everything he had till he was 27 years old. Then realized he had to love himself and who he was or quit living at all. My friend is as genuine as you can be. He goes to an accepting church. He was never abused or influenced by other factors his brothers weren’t. He can attest that he had zero choice in the matter. The last thing I want for my friend is people trying to tell him he’s weak, deranged, flawed or could have been rescued from the good life he is living right now if he “just wanted to be “. I’m all about research but I don’t really need results of a study to inform me that this man was born to be who he is. His friendship has has made a positive difference in my life and my family and many others. If he had taken a different fork in the road at 27 the world wouldn’t be a bette place. 

I am less familiar but aware of others who may have been influenced by being raised around all women and ended up gay. I don’t think you can fix them either but would be interested in seeing a study about that as well. 

Out of likes but well said Alexava👍