We defined sex as purely biological, consisting of physical human anatomy. This definition, in contrast to its "opposite," implies that gender does not have such an objective existence; it does not have an innate, comprehensive form, rather it consists of mere subjective expressions. In this sense, while we are objectively bound to our sex (ignoring the issue of transgenders), we are free to choose our own gender. This freedom to choose implies a conscious decision, which I found problematic during our discussion. I do not find it realistic that such an intentional consciousness is present when expressing a gender identity. If consciousness is absent, however, its lack of presence would not imply freedom, but rather a substantial innateness.
Ben provided a counterargument, suggesting that culture and society has, in a sense, stolen our subjectivity and subsequently informs our perceptions of what is considered "normal." I agree with this statement, to a degree. Modern culture, insofar as it is an extension of ourselves, informs our perspective of the world to a large degree. However, the problem with this argument, I find, is that it does not leave room for social change, which itself becomes the strongest argument for an innate gender. If society provides the definitions that we must adhere to, why would anyone instigate change? Unless people are reacting for the sole reason of rebellion (which I do not think is the case), then such desires to change the norm must stem from an innate inclination to change the standard...which would imply a certain objectivity within the definition of gender.