Cisgender men and women have different brain structures, and transgender people's brain structures tend to resemble that of the gender that they identify as[1]. So, for example, a trans woman like myself who was born male will have a brain structure that resembles that of a cis woman, not a man.
> I know a trans man who, after a few months of testosterone, claimed it was "night and day" in how they felt about and processed the world
This has been my experience as well (except, the opposite direction, obviously). The way I look at it, before I realized I am transgender, when testosterone was the dominant sex hormone in my body, it was like putting the wrong fuel in a car. It caused a whole slew of serious mental health problems. Estrogen has allowed me to think more clearly, and process thoughts, feelings, and emotions like I never could before. I'll never go back.
Cisgender men and women have different brain structures, and transgender people's brain structures tend to resemble that of the gender that they identify as[1]. So, for example, a trans woman like myself who was born male will have a brain structure that resembles that of a cis woman, not a man.
> I know a trans man who, after a few months of testosterone, claimed it was "night and day" in how they felt about and processed the world
This has been my experience as well (except, the opposite direction, obviously). The way I look at it, before I realized I am transgender, when testosterone was the dominant sex hormone in my body, it was like putting the wrong fuel in a car. It caused a whole slew of serious mental health problems. Estrogen has allowed me to think more clearly, and process thoughts, feelings, and emotions like I never could before. I'll never go back.
1. https://health.clevelandclinic.org/research-on-the-transgend...