This is a March 2014 study and I am not able to read it online yet.
In the past, researchers have found that people with gender identity disorder are more likely to have autism spectrum disorders than the general public. This study came at the question from the other direction. They looked at children with autism spectrum disorders (ASD), attention deficit hyperactivity disorder (ADHD), or a medical neurodevelopmental disorder to see if they were gender variant.
They measured gender variance by scores on the Child Behavior Checklist (CBCL) that parents had filled out. They compared the children’s scores to two control groups and the standarized scores for the CBCL.
The study found that children with ASD and ADHD were more likely to express gender variance, at least as measured by the CBCL. The children with medical neurodevelopmental disorders were not more likely to be gender variant.
This is a very intriguing, although limited, result. These children were not actually tested to see if they had gender dysphoria. What exactly does it mean that they had more gender variance than other children? Were they more likely to play with children of the opposite sex? Did they prefer toys and activities we see as suitable for the opposite sex? Did they dress differently than other children?
The big question here is whether or not these children actually wanted to be the opposite sex. If not, they did not have gender dysphoria.
Another important question is whether the children were naturally more like the other sex or just didn’t understand the socially approved gender roles, either due to ASD or to not paying attention.
On the other hand, given that children with gender dysphoria are more likely to have ASD than usual, it might be that children with ASD have more gender dysphoria than we realize.
An interesting tangent – there may be a link between ASD and ADHD. It’s not clear if they share an underlying cause or genetic predisposition or not. If there is a common cause, might it also be linked to gender dysphoria?
As usual, we need a follow-up study in this area. A useful study would look at what percentage of children, teens, and adults with ASD or ADHD have gender dysphoria.
Increased Gender Variance in Autism Spectrum Disorders and Attention Deficit Hyperactivity Disorder by Strang JF, Kenworthy L, Dominska A, Sokoloff J, Kenealy LE, Berl M, Walsh K, Menvielle E, Slesaransky-Poe G, Kim KE, Luong-Tran C, Meagher H, Wallace GL in Arch Sex Behav. 2014 Mar 12.