Autism, sexual orientation and gender identity: what the studies say

What the data show

The largest study published so far on sexual orientation and autism was carried out by the Autism Research Centre at the University of Cambridge. The team, led by Elizabeth Weir, Carrie Allison and Simon Baron-Cohen, surveyed 2,386 people aged between 16 and 90. Of these, 1,183 were autistic.

The findings, published in Autism Research in 2021, showed that autistic people were less likely to identify as heterosexual and more likely to identify with other sexual orientations. In particular, they were around eight times more likely than non-autistic people to identify as asexual or to select the category "other sexual orientation".

The study also found differences between men and women. Autistic men were 3.5 times more likely than non-autistic men to identify as bisexual. Autistic women were three times more likely than non-autistic women to identify as homosexual. Within the autistic group, women were also more likely than men to identify as asexual, bisexual or as having another sexual orientation.

Other studies using different samples and methods have found the same pattern. In 2018, Rita George and Mark Stokes used the Sell Assessment of Sexual Orientation, which measures not only the label a person uses but also the attraction they experience. In the autistic group, nearly 70% fell within a non-heterosexual orientation, compared with around 30% of the comparison group.

The figures differ because the studies do not ask exactly the same questions. Some measure how people identify. Others measure attraction or relationships. However, they all point in the same direction: homosexuality, bisexuality and asexuality are more common, and heterosexuality is less common, among autistic people than in the general population.

Gender identity

Studies also find greater gender diversity among autistic people. One of the largest studies was led by Varun Warrier and published in Nature Communications in 2020. The team brought together five datasets containing information from more than 640,000 people.

The results showed that transgender and gender-diverse people were between three and six times more likely to have an autism diagnosis than cisgender people.

This does not mean that autism causes a transgender identity or that being transgender causes autism. The study found that the two occur together more often, but it did not investigate why. The authors themselves stressed that the findings should not be interpreted as showing a causal relationship. Two points are therefore clear: the association appears consistently, and researchers still do not know why it exists.

Why does it happen? Possible explanations, not firm answers

There is no proven explanation. Researchers have suggested several possibilities, but none of them can yet explain why sexual and gender diversity are more common among autistic people.

Researchers have proposed that some autistic people respond differently to social expectations about gender and relationships, or are more likely to report identities that other people conceal. The studies cited here did not test this explanation directly against alternatives, so it cannot be presented as a proven cause.

The findings of George and Stokes are consistent with this possibility. When people are asked about attraction rather than only about the word they use to describe themselves, more diversity appears, including among non-autistic people.

Biological factors, differences between samples and the way questions are asked are also being investigated. Current findings cannot establish one explanation or show causation. The association is documented; its causes remain uncertain.

How the figures should be understood

Two points are important when reading these findings. The first is that the percentages change depending on how sexual orientation is measured. The George and Stokes study, which used a scale to assess attraction, found that nearly 70% of the autistic group had a non-heterosexual orientation.

Surveys that ask people directly, "How do you identify?" usually produce lower figures. This is not a contradiction. A person may experience attraction to more than one gender and still identify as heterosexual, bisexual or without any particular label. For this reason, current evidence does not allow us to say that most autistic people are heterosexual or that most are LGBT+. What can be said is that sexual diversity is more common among autistic people than in the general population.

The second point concerns gender identity. Most autistic people are cisgender. Even so, the proportion of transgender and gender-diverse people is much higher than among non-autistic people. Sexual orientation, gender identity and autism are different parts of a person's life. Studies show that they occur together more often than expected, but none of them explains the others on its own.

What this means in daily life

For an autistic adult, knowing these figures may help place their experience within a wider pattern found in large studies and in different countries.

The researchers recommend that sexual education and healthcare appointments use language that includes all sexual orientations and gender identities naturally. Professionals should not assume that an autistic person is heterosexual or cisgender. Nor should a person's sexual orientation or gender identity be treated as confusion caused by autism. Being autistic does not make someone less able to know what they feel.

Families can ask which name and pronouns the person uses, respect confidentiality and help them obtain healthcare without treating autism as a reason to dismiss what they report.