I have to confess: transgender issues break my paradigms. Here’s the question: does a boy (or man) stop being a man once you cut off his genitalia? In reverse, does a girl become a boy when you add a different body part? What determines sex or gender?
Definitions: As usual, a lot of this depends on your definition. Wikipedia describes gender as the social, behavioral, and cultural concept of male/female as based on the World Health Organization. Gender, essentially, is what everyone else says about you and how you should be have as related to your sex. Gender identity, then, is what you say about yourself (and note that this is related to, but not the same as, sexual orientation) as related to your sex. Discussions regarding gender are really discussion of societal, social, cultural and even theological norms as they relate to male/female roles.
Sex, on the other hand, refers to the biological/physiological side of things. According to the wikipedia article, sex is determined by which gametes the organism produces: if you produce sperm, you are male, if ova, then female. Alternatively, we can determine sex on a genetic level based on inherited genes.
Implications: Technically, we lack the ability to reassign sex. Even if you cut off male genitalia and give hormone therapy, you cannot change the genetic makeup of the individual. As such, sex cannot change, because the biological factors that make one male or female cannot change. As an extension of that, I don’t see how we can attribute sex to sexual preference. While there are theological implications of same-sex attractions, it seems difficult to me to assert that attraction to one sex automatically equates to self-identity as the opposite.
The talk about “Biblical manhood or womanhood” seems misplaced to me. While we might develop a theology of gender roles, we have to remember that (1) theology is always contextualized, (2) theology is humanity’s response to what God has revealed, meaning God may not have explicitly stated thoughts about manhood and womanhood, (3) we can discern ideas about manhood and womanhood consistent with the rest of our understanding of divine revelation and (4) whatever conclusions we come to regarding gender (as opposed to sex) are by necessity mediated through our own understanding of culture, our own family experiences, and our own personal growth and development.
Conclusions: When is a boy a boy? My son is a boy because his chromosomes include my “Y” in addition to his mother’s “X”. He has (eventually) the ability to produce male gametes (sperm). He is a boy because I tell him he is a boy, based upon my understanding of family history, societal norms, theological principles, and cultural expressions (not necessarily in that order). His boyness may be somewhat related to whom he will find attractive (and I have definite ideas of what that should be) but these are not linked by necessity.
My son is a boy because he is a boy; I (and the rest of society), help him to understand what that means.