What do people mean when they talk about identity as separate from material conditions?

I am not so much invested in QT really, and most of my readings are of second or third order. But one of the thing that I know QT is about is that categories like sex, gender, sexuality etc are socially constructed, and QT is actually all about the deconstruction of these seemingly stable categories and critique of the associated identities. The only place that I have read the "innate gender identity" and the male-female brain thing being associated with QT is when I started browsing reddit some months ago. I do not understand how it can have anything to do with QT. Quite the opposite, in the past there have been many queer criticisms to such notions. For me, all this is just reflected biological essentialism.

/r/GCdebatesQT Thread