@LaetiBlabla: It means charting out huge numbers of sex-dimorphic (measurably different for men and women) sites and attributes and finding that it results in two overlapping bell curves. One correlates with the general category of "male" and the other with "female", although they actually fall upon a spectra (hence the dumbell/overlapping bell curves). There are 20+ known sites & attributes in the brain alone & they strongly tend in aggregate to match a person's identify as male/man or female/woman. Interestingly, they do not necessarily have to match the one site of the body used by a doctor to assign sex at birth (although they do up to 99.7 % of the time when a binary classification is used).
So, a "male" brain is simply one that shows more sites falling on the male end of the spectrum or chart & vice-versa for a "female" one. But that is so generalized as to be useless. In reality, many people are spikey, with some attributes matching their social sex/gender (based on Western ideals of the category) and some not, to various degrees.
And then there is the identity issue itself. We are our brains. Any other body part can be removed or modified (assuming it doesn't kill the person) and they still remain themselves, with their sense of "male" or "female" (on a spectrum or many). But damage certain brain sites and that changes. So it seems it comes down to those sex-dimorphic sites, the very low level, hardwired ones like where your sense of Self is located (damage it and you don't know you from other) and the brain's map of the body (*not* the same as the high level, semi-plastic one used to keep track of where a known part is at any one moment). Really, then, what it ultimately comes down to is the brain of someone who knows they are male is a male/man's brain and that of someone who knows they are female/woman being a female/woman's brain, by definition.
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