Why There Almost Certainly Is No Non-Binary Brain

These conclusions are based on the theory of brain sex, that claims that sexual differentiation of relevant areas of the brain is responsible for the feeling of being male or female.

During pregnancy, the fetus needs hormones to develop healthily. An effect of hormones is of course the development of sex. Not just physical sex, but also “brain sex”, or the sexual differentiation of the human brain. Multiple aspects of the human brain are found to be sexually dimorphic, where testosterone causes a masculinization of these areas, while an absence of (a high amount of) testosterone results in feminization. This happens separately, and at a later time, than the determination of physical sex. This could explain transsexualism; the brain develops a different “gender” than the body by (presumably) some mess-up in hormones. This is supported by studies on untreated transsexual brains, that found that areas related to body perception reflected the gender the transsexual person identified with, rather than their birth sex.



Agender people claim to be genderless, to be neither. It is also important to note that these people are otherwise physically healthy and developed healthily during pregnancy. For this to be real, that would mean no sexual differentiation of the brain, and thus no gender identity. And for this to happen, no hormones should play any part in the development of the fetus, because the presence of any hormones would result in either a masculinization or feminization of the brain.

Low hormone levels, however, are highly dangerous to a developing fetus. Estrogen is responsible for one of the major processes of fetal maturation. Without it, a fetus’s lungs, liver and other organs and tissues cannot mature. Furthermore, estrogen also regulates progesterone, ensuring a healthy pregnancy. A lack of this hormone is linked to serious complications and miscarriage. And we need the complete absence of hormones to explain a brain that developed completely without gender identity.

In mammals, it is also said that female is the “default”, because the elimination of any information necessary for male development results in female. You could say that if you take away all or most hormones, the fetus would still develop as a female, not genderless. Quoted from this source also: “No hormones have yet been discovered that are necessary early in life to produce female sexual development”, another point that supports this theory. A human either develops a feminized brain, or, from surges of testosterone during pregnancy, a masculinized brain.

This also helps disprove “bigenderism” as a physical thing; the brain’s sexual differentiation stays female or develops towards male, not both at once. There is also absolutely no proof it is possible to develop an “inbetween” or “genderqueer” gender identity; research on transsexual brains already shows they aren’t 100% masculinized or feminized [1] [2] yet despite this, the patients still identified as purely male or female, meaning that a brain that can be interpreted as being more “inbetween” doesn’t result in an “inbetween” or “genderqueer” identity.



Additionally, it is not just hormones that contribute to the development of “brain sex”, therefore even the absence of hormones might not be enough to become “genderless”.



With this information we can say that:

1) it is extremely unlikely that a fetus would survive a pregnancy without the presence of hormones, and if it did, that it would develop without any complications.

2) even if we assume #1 to be false, we can still assume the fetus would likely develop in the “default” way and become female, as there are other factors that cause sexual differentiation of the brain.



From this we can conclude that “non-binary" identities are either completely impossible or highly unlikely to develop in a human brain.