The fight for transgender equality is nothing new; it dates back to the late ‘60s/early ‘70s with Sylvia Rivera and Marsha P. Johnson. However, with trans celebrities such as Laverne Cox and Caitlyn Jenner, activists like Gavin Grimm and even a National Geographic cover story, mainstream America is learning more about what it means to be transgender. However, not everyone is convinced being trans is a thing. Just look at the YouTube comment section on any video about trans stuff, and you’ll see the same bad arguments: “I identify as a tree, so I must be a tree!” “Penis = boy, vagina = girl, get over it!” “You can cut your dick off, but you still have XY chromosomes, so you’ll always be a man!” It’s ironic that transphobes try to use science to back up their claims because science actually shows the opposite: there is a scientific basis for gender identity, but it’s not what’s in your pants.

The most recent study was published in the Journal of Neuroscience in 2014. In this study, researchers from the Medical University of Vienna used diffusion-based magnetic resonance tomography (MRT) brain scans on both cisgender (non-transgender) and transgender men and women to compare the neurological differences between the subjects. The study concludes, “The results of this study show that the white matter microstructure in FtM and MtF transsexuals falls halfway between that of [cisgender women] and [cisgender men].” What does that mean? Amanda Koehn of Ravishly.com explains it like this:

A trans woman has significantly different brain movement than a cis man, despite having the same biological sex. Moreover, trans men and trans women were different from each other, implying that the brain shows a wide range of gender based differences, rather than simply male or female.

Another study with similar results was published in 2011 by the Journal of Psychiatric Research. For this study, psychobiologists and neuropsychologists from Spain did MRI scans on 18 trans men, 19 cis women and 24 cis men. The study concludes, “Our results show that the white matter microstructure pattern in untreated (pre-transition) FtM transsexuals is closer to the pattern of subjects who share their gender identity (males) than those who share their biological sex (females).” What’s interesting to note about this study show trans men’s brain patterns are similar to cis men’s before trans men undergo medical transitioning.

So far all of the scientific literature about trans people have focused primarily on binary trans men and women; there’s very little research on non-binary trans people. The closest scientific study anyone has done is a 2012 paper published in Medical Hypotheses that is a survey 32 individuals who identify as bigender. According to results, 14 participants said they involuntarily “switch” their gender identities on a frequent basis. The study also reports that two-thirds of the participants experienced moderate “phantom body parts.” The authors hypothesize that gender fluidity might be a “neuropsychiatric condition,” but it’s just a hypothesis until there’s more research.

Sadly, the lack of research on non-binary gender identities has led to many non-binary people feeling ostracized by the trans community for not being “trans enough,” and being called “transtrenders” by online trolls. However, many licensed gender therapists agree that non-binary trans people are and should be included under the transgender umbrella. For example, UK-based gender therapist Christina Richards co-wrote a paper published last year in the International Review of Psychiatry where she argued that because the DSM-5 describes gender dysphoria as, “A strong desire to be of the other gender (or some alternative gender different from one’s assigned gender),” this includes non-binary people.

“But how does this happen?” you may ask. “Why causes people to be trans?” At this point, it’s hard to say, but science does give us some clues. Back in 2015, journalist Amy Ellis Nut gave an interview to NPR to discuss her book Becoming Nicole: The Transformation of an American Family. She told NPR that gender identity development begins prenatally, and that “many things can influence the environment of the womb, and the environment of the womb influences the level of hormones and the chemicals that go into the development of a fetus.” What those things are, Nutt doesn’t say, but we can assume that trans people are in fact, to quote Lady Gaga, born this way.

The science behind being trans is still developing, but from what evidence we have so far, it’s clear that trans people aren’t just “making it up.” Also, despite what Ben Shapiro thinks, being transgender is not a metal disorder. (If it were, why does the American Psychological Association say trans people “are more likely to experience positive life outcomes when they receive social support or trans-affirmative care” instead of conversion therapy?) Of course, even if I’m wrong, hopefully we can all agree on one thing: Don’t be a transphobic asshole, okay?

Trav Mamone is a queer trans blogger who write about the intersections of social justice and secular humanism at Bi Any Means. They also host the Bi Any Means Podcast and co-host the Biskeptical Podcast.