This post is part of Outward, Slate’s home for coverage of LGBTQ life, thought, and culture. Read more here.

Gender specialists first noticed decades ago that a large number of people who seek treatment for gender dysphoria also seemed to have autistic traits. Research on this phenomenon goes back to at least the 1990s, when the first case study of an autistic child with gender dysphoria (then called gender identity disorder) was published. As studies investigating the co-occurrence (or correlation) between gender dysphoria and autism spectrum disorder (ASD) have trickled in, there is a growing consensus in the medical community that the two do co-occur at disproportionate rates. This consensus is based on numerous studies reporting that gender-dysphoric youth are more likely to be autistic than would be expected based on autism rates in the general population. (This may also hold true for adults, although the research on adults is sparser.) This co-occurrence has implications for the treatment of both gender dysphoria and autism in young people, and hints at a connection between the biological causes of both transgender identity and ASD.

Gender dysphoria is the feeling of incongruence between the sex assigned at birth and the gender a person identifies with. Many people who experience gender dysphoria identify as transgender. Some trans people fit into the gender binary (in the case of trans men and trans women), while others identify as gender nonconforming or nonbinary (meaning they fall somewhere between or outside the man-woman divide).

“We have enough evidence, across multiple studies internationally, to say that autism is more common in gender-diverse youth than in the general population,” said John Strang, a neuropsychologist and founder of the Gender and Autism Program at Children’s National Health System in Washington. Strang authored a 2014 analysis that found that more than 5 percent of autistic youth sampled for his study also displayed some level of desire to be the other gender, according to parental reports. (He cautioned that it’s too soon to say what the exact percentage in the overall population may be.) Another widely referenced study found that 7.8 percent of young people being treated for gender dysphoria at a clinic in Amsterdam had a confirmed diagnosis of ASD.

These studies seem to support the hypothesis that transgender identities are rooted in biology, especially when combined with other studies pointing to a strong heritable component of transgender identity. A biological basis for transgender identity is still highly contested, although the science has been pointing toward that explanation for several years. Researchers believe that autism itself is highly heritable, so a link between autism and gender identity could even provide some direction for researchers hunting for genes associated with transgender identity.

On the other hand, it’s possible that autism is overrepresented among trans youth because autistic people are less concerned with social norms and less likely to bow to social pressures that keep other trans people from coming out. Our ability to study gender dysphoria and diversity is limited by the fact that there are such strong social pressures, starting in early childhood, to conform to gendered expectations. There’s no way of knowing how many people hide their transgender identity, so we can’t know for sure whether studies of openly transgender people are representing the full picture at this time.

It’s possible that autism is overrepresented among trans youth because autistic people are less likely to bow to social pressures that keep other trans people from coming out.

One common characteristic of autism is that autistic people often may have what’s called “overfocused interest” in subjects that are dear to them. At least one researcher has suggested that autistic people’s gender dysphoria is really an overfocused interest in gender, but the majority of professionals who work with this population disagree that this theory is sufficient to explain the co-occurrence. More than 20 of these experts worked together on a paper providing clinical guidelines to help address the needs of patients with both autism and gender dysphoria, and they found that autism should not preclude a diagnosis of gender dysphoria or prevent a patient from accessing transition-related medical care. “Certainly, you can find cases of kids for whom some aspect of autism seems to be driving gender dysphoria. But over time, we’re seeing that a good number of neurodiverse teens coming into gender clinics truly are transgender or gender diverse,” Strang said.

One practical outcome of this research is that clinicians are recommending that autistic youth should be screened for gender dysphoria—and that clinics that work with gender-dysphoric youth should screen clients for autism as well. Young people who are found to have both need individualized, compassionate care, and they and their families also need to know that they are not alone. Strang cautioned that ASD should not be viewed as a negative for transgender people, because the ability to ignore social pressure can be very freeing for this group: “Autistic people may be more bold and individualistic, less swayed by social expectations. Some of the front-line leaders of the trans rights movement have been trans and autistic—and there’s a beautiful focus, for many of them, on being themselves and not bending to social expectations of what others expect them to be.”

Reid Caplan, a transgender man who works for the Autism Self Advocacy Network, stressed to me that autistic people can understand their own gender identity and make decisions about transition for themselves. He further noted that some therapies for very young children with autism have an unnecessarily gendered aspect to them. Caplan rejects the idea that autistic children, transgender or cisgender, should be forcibly socialized into restrictive gender norms.

“There are pictures of me being taught to play with dolls, as part of my therapy, and needless to say I am not looking very happy in those pictures,” Caplan said. “There are also therapies around clothing, helping autistic kids get accustomed to wearing different clothing, and often that centers on a skirt or a dress for a girl and a suit for a boy. Regardless of whether that child is trans, there shouldn’t be any emphasis on gender role for any of the therapies for autistic youth.”

Beyond that, Caplan suggests that our culture should be more open to letting autistic people explore gender rather than invalidating their gender identity because they’re on the spectrum. This accords with the views of clinicians working with people who have gender dysphoria and autism—and with common sense. People with autism have as much right to self-determination as anyone else. And whether autism is genetically linked with gender dysphoria or not, there’s no evidence that autistic people are less likely to benefit from gender transition than anyone else.