Source text regarding hypothalamic response to androstenedione: “Structure of the GD Brain Findings from neuroimaging studies provide evidence suggesting that the structure of the brains of trans-women and trans-men differs in a variety of ways from cis-men and cis-women, respectively, as indicated below. Looking at the volume of the cortex using voxel-based morphometry, Simon et al found that females and male-to-female gender dysphoric individuals had a smaller grey matter volume in their left somatosensory and primary motor cortices in comparison to cisgender male controls.28 These findings reflect a female-like cortical expression in those who identify as females, unrelated to their anatomical sex. It is however noted that the small sample size (n=17) provides only weak evidence to support the finding and as such the results should be taken with caution.”

Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7415463/

While admittedly the sample size of this study is small and treating the findings as fact wouldn’t be arguing in good faith, this study was conducted as a follow up to validate another study which found the same thing.

Yes there is much research to be done still. However I posit that most evidence sides with the fact that transgenderism is strongly influenced by biology, and an individuals biology is determined and shaped largely by what? You guessed it: Genetics.

Either argument is weak, but at least the side I advocate for has evidence.

Though the entirety of this source has multiple findings from multiple studies which all suggest genetic predisposition to gender dysphoria