You say no transwomen believe this it has been called a riddiculous straw man Yet if one goes to tsroadmap com and or lynnconway com and googles in the search boxes you would see on their pages brain sex they will get many hits Read The theory that prenatally established brain and CNS structures determine innate gender feelings and gender identity It appears that if those brain and CNS structures are masculinized in early pregnancy by hormones in the fetus then the child will have male percepts and a male gender identity independent of whether the genes or genitalia are male If those structures are not masculinized in early pregnancy the child will have a female percepts and a female gender identity again independent of the genes or genitalia As in the case of intersex infants having ambiguous genitalia there are undoubtedly many degrees of cross gendering of brain and CNS structures so that while some infants are completely cross gendered others are only partially cross gendered verbatim This is basically the feminine essence theory When one adds that there is only one way to be cross gendered in the brain and that cross gendering must be totally separate in any and every way from sexualorientation That there is in essence one way to be feminine that is the feminine essence theory Interestingly if I understood JamesCantor correctly in a conversation we had on my talk page This is very close to what he and sexologist like him belive However they contend that the way in which a brain is cross gendered depends on sexualorientation Thus take a homosexual male Homosexual males have been shown to think and have some brain structures like those of straight women A homosexual transsexual is just a case where there is more enough female brain structure present to make a person mentally female While non homosexual transsexuals if I understood correctly also have cross gender structures in their brains just not the same as a homosexual transsexuals The non homosexual MTF transsexual brains retaining more masculine brain structure That is the crux of the problem isn t it now That Blanchard s theory not only contradicts the feminine essence female brain sex theory of MTF transsexualism but it then says ok one kind of transsexual really does work that way So much heat and anger caused by so little