New large scientific study shows that sexual orientation is the end product of many factors, genes included
The New York Times report on a new large scale study on how genetics may affect same-sex behavior. The study confirms what many of us have argued for some time now, that sexual orientation and behavior are most likely caused by an interaction between genetic, hormonal, environmental, social and psychological factors. I suspect the same is true for transgender and nonbinary identities.
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 whethersomeone 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.
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…
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.
In an op-ed Steven M. Phelps and Robbee Wedow (gay men and researchers in biology and sociology) argue that it is important not to overstate the role of genes:
The study found that genetically related people tend to be similar in their behavior, which tells us that sexuality has influences buried somewhere in the DNA. But when the researchers tried to add up the contributions of each DNA variant they examined, they could predict less than 1 percent of the variation among study participants.
Many LGBTQA activists have argued against this kind of research as it may be used by transphobes and homophobes in their attacks against rainbow people. Phelps and Wedow discusses this problem, but concludes that “bigotry needs no data”:
No facts will sway those who want to police the intimacies of consenting adults. Rather than consign ourselves to ignorance out of fear, we should use these powerful new data ethically and thoughtfully to arrive at a fuller understanding of who we are.