Monday, August 31, 2015
One of the informal prerequisites for the court to deem something a suspect class for purposes of equal protection is that the members of that class have an "immutable trait," something that they are born with and is not amenable to change.
As its name suggests, transgender implies an identity that is mutable. However, a recent NYT story challenges that inference.
Dr. Kranz studied four different groups: female-to-male transsexuals; male-to-female transsexuals; and controls who were born female or male and identify as such. Since hormones can have a direct effect on the brain, both transsexual groups were studied before they took any sex hormones, so observed differences in brain function and structure would not be affected by the treatment. He used a high-resolution technique called diffusion tensor imaging, a special type of M.R.I., to examine the white matter microstructure of subjects’ brains.
What Dr. Kranz found was intriguing: In several brain regions, people born female with a female gender identity had the highest level of something called mean diffusivity, followed by female-to-male transsexuals. Next came male-to-female transsexuals, and then the males with a male gender identity, who had the lowest levels.
In other words, it seems that Dr. Kranz may have found a neural signature of the transgender experience: a mismatch between one’s gender identity and physical sex. Transgender people have a brain that is structurally different than the brain of a nontransgender male or female — someplace in between men and women.
This gradient of structural brain differences, from females to males, with transgender people in between, suggests that gender identity has a neural basis and that it exists on a spectrum, like so much of human behavior.