ABSTRACT
Let’s begin with what we know to be true. There are two and only two sexes, right? And you know with certainty which one of the two you are, I’m sure. Have you ever stopped to consider how you know what sex you are? It sounds pretty simple; just a quick check of the genitalia is all it takes. It’s actually not so easy to draw a binary distinction between the sexes, despite common belief, given that so much variation in genital and other sexual anatomy occurs with great regularity. If that is the case, in this era of many states altering their constitutions to permit only women and men to marry one another, then we must have means to unambiguously define someone as a woman or a man. Most often, as noted above, we consider external genitalia to be the unequivocal sign of anatomical sex. In fact, a cursory examination of the genitalia is typically how sex assignment occurs at birth.
