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Cambridge University Science Magazine

An article published in Science two years ago aimed to estimate how likely someone might be to inherit same-sex behaviour from their biological parents, involving one of the largest data sets ever used to search for genes connected to same-sex sexuality. The researchers and press claim that their findings are an important, progressive step in protecting LGBT+ people. However, this study took fundamentally flawed approaches that endanger LGBT+ people.

The authors used nearly 500,000 DNA sequences from people in the UK, USA, and Sweden, to perform a genome-wide association study (GWAS), a technique that links up genes with individual traits. Specifically, they scanned DNA sequences for any variation that correlated with the participant’s answer to the question 'Have you ever had sex with someone of the same sex?'. Reducing queer sexuality to same-sex sex in majority white, Western countries is so lacking as a premise that their sweeping conclusions should be read with caution.

This study formulates itself as a response to the “gay gene” hypothesis which grew out of a fluke result in the 90s that linked homosexuality to a single gene. This finding has never been replicated and has since been dismissed scientifically, but at the time gathered a lot of attention. This recent GWAS paper reconfirms that, like most behaviours, there are thousands of DNA sites that contribute to same-sex sex, rather than any one particular gene or cluster of genes. Furthermore, same-sex sexuality is not fully explained by genetics – the authors estimate that genetic variation might contribute only 8 - 25% to the trait. By reconfirming that sexuality is genetically complex, the authors argue they are curtailing discrimination.

However, in today's era of tech-driven surveillance, data like this will be (mis)used to identify LGBT+ people, with consequences ranging from scams and misinformation to social engineering and persecution by the state.

Shortly after the study was released, GenePlaza, a self-described 'marketplace for genetic reports', hosted an app called 'How Gay Are You?' based on the study, with US entrepreneur Joel Bellenson charging $5.50 for quack diagnostic tests. This app was only removed after a month of campaigning by eminent LGBT+ geneticists and the rallying support of the science community. Given that members of the consumer DNA-testing company 23andMe co-authored the study, it is hard to imagine they did not see this coming.

Queer participants in this research probably never imagined their data would be used this way. The use of UK Biobank data was publicly criticised since participants only consented to "health-related" research. The authors claim their research fits this criterion since LGBT+ people are disproportionately unhealthy, but this is widely accepted as due to the impact of social oppression, not genetics, making this claim dubious. Ethics committees overlooked the flaws of releasing this sensitive information, perhaps due to the history of queer medicalisation: homosexuality was only formally delisted as a psychiatric condition some 20 years ago, and conversion therapy, transmedicalism, and corrective hormone therapies for bisexuality and asexuality in particular are all still booming.

Accessing resources and funding to test whether queerness is biomedically diagnosable whilst claiming it is for the health of communities is an example of pinkwashing: where institutes display an outwardly queer-friendly image in order to distract from the ways they harm people and work towards capitalist interests. The authors repeatedly bring up how they consulted LGBT+ people and commissioned a sociologist to write a perspective piece about their study in their defence, posturing behind a blessing of sensitivity whilst ignoring the material reality that their work will be used by an unfair society. These researchers opened the floodgates for harmful agents with this study, whether by ignorance or intent, by testing if someone's DNA sequence could be used to predict same-sex sexuality. Importantly, this had only an estimated 1% success rate.

The fear of data like this being used to surveil queer people is not unfounded; this GWAS research is part of a wider trend. A recent study at Stanford used machine learning to estimate whether over 6,000 people were gay or straight by classifying a single photo of their face lifted from a dating app. The AI program outperformed humans easily: whilst people could guess with up to 61% accuracy, the algorithm was 81% accurate and could improve to 91% when given a few more images. The authors then began interrogating which facial features the protocol had identified, work reminiscent of racist, pseudoscientific craniology from the 20th century.

The pop-sci "problem" with gay evolution

Real-world consequences notwithstanding, the academic justification for researching gay genes is also flawed. Homosexuality is popularly framed as an evolutionary paradox under the assumption that gay people would reproduce less and therefore not pass on their genes, ultimately leading to the self-annihilation of gay genes. This paradox is usually resolved by scenarios involving heterosexual saviours; perhaps gay genes wire people towards caring for the children of their heterosexual siblings and can therefore sustain their families' gay genes (a Darwinian idea known as "kin selection"), as suggested in the YouTube video 'Does Everybody Have A Gay Gene?' by the pop-sci channel AsapSCIENCE. This embeds the real-world social hierarchy of straightness over gayness in a scientific model by deciding that gay genes exist for the benefit of straight people.

The obvious scientific flaw with this idea is that gay people are not sterile. Moreover, the idea only exists when bisexuality is ignored. Overlooking, minimising or outright denying the existence or importance of bisexuality, a phenomenon termed bisexual erasure, is something found in every area of society and evolutionary genetics is no exception. Even if we humour the suggestion that homosexuality reduces reproduction, there is still no reason to imagine that bisexuality would be any less reproductive than heterosexuality. The reality is that the available evidence simply shows that same-sex sexuality is likely to be evolutionarily ancient – a suggestion already put forth by the abundant evidence of bisexuality across the animal kingdom, and reinforced by this study showing that associated variant sites are distributed widely across the human genome.

Together, the unethical use of personal data, the study playing into exploitative capitalist interests, and the shaky theoretical foundations premised in bi-erasure render this study, and others like it, disappointing and dangerous.

This approach to the genetics of sexuality has been influenced by a conflict in liberal LGBT+ movements. The mainstream movement wants to insinuate that sexuality is determined, "born this way", so to speak, and therefore not a choice – a defence against homophobic violence such as conversion therapy. Writing for the Guardian on this GWAS study, gay rights activist Owen Jones wrote 'such research is surely irrelevant' and that 'believing that LGBTQ people choose their sexuality belongs in the same bin as flat-Earthism and climate emergency denial.'

Aside from the harms of a "born this way" hypothesis to queer people's self-concept and politics, in science the "born this way" hypothesis enables studies like this to pinkwash their material outcomes: dressing up their aims as looking for the genes that lead to LGBT+ people being"'born this way" whilst creating ways to surveil and restrict LGBT+ people. Scientists interested in sexual biology must face up to the complexity of this situation before ploughing ahead with harmful research, and in broader society we can work towards justice and queer liberation whether our sexuality is decided by birth, environment, or choice.

Chay Graham is a first year PhD student studying Evolutionary Biology at the University of Edinburgh, having just graduated from the Natural Sciences Tripos, and a former community organiser in the disability rights movement within Cambridge. Artwork by Eva Pillai.