There is a new article in the open-access online journal PLoS One that adds to the growing catalog of data demonstrating that trans brains differ from those of their biological cis counterparts.
In the study, Simon et al., (2013) performed MRI brain scans of both MtF and FtM trans individuals, as well as scans of biological cis controls. They established volume measures of certain grey matter (GM) areas, looking for areas of variance. The result?
The post hoc analyses of the significant clusters with GID × Biological gender interaction showed that transgender patients had significantly different regional GM volume from that of controls sharing their biological gender and did not differ significantly from that of controls sharing their gender identity in the examined clusters
In other words, trans brains more closely resembled the brains of their gender identity, not their assigned gender.
This is not a completely unprecedented result; researchers have discovered brain differences in transfolk before, though there are older grey matter studies that would seem to contradict these findings. It’s also worth noting (and the study itself says this) that only so much can be inferred from these findings, as the sample size — 17 individuals — was so small. Still, as the researchers put it:
The limited sample size may indeed limit statistical power, however it helps to pinpoint clear trends in the data that can be validated by further investigations.
It’s hard to say that the question, “Are trans brains different?” has been definitively answered, but with every study it seems increasingly likely that the answer is yes, and that the questions that really need to be answered are how different? and why?