you are right to correct my statement because it is not that definite. although, that doesn't mean that what follows is something i disagree with.
rather than saying 'the more we categorize the less they are able to self identify', i should have said something more along these lines: the more we categorize, the more self-identification that deviates from the norm is considered to be 'wrong' or 'inappropriate'. i suppose it is the connection between self-identification and self-expression in the context of social norms that i wanted to highlight.
i agree that gender identity can be (is?) fluid.
that broader range of possibilities is exactly what i was pointing to in the criticism of categorization (albeit misplaced in identity rather than in expression of that identity). whether biological or social in origin, it is the social construct of the 'other' that creates the barrier to inclusion. the social construct aspect of the way we see gender is crucial.