Doug, I read this through a few times over the past couple of weeks. It bothered me right away from a "first principles" point of view, but I did not - and still do not - want to argue everything all at once, but ordering the points is difficult. So this is not a pyramid, but a mosaic.
As Ayn Rand pointed out in "Racism" even if it were established that overwhelming percentages of this group or that posssesed or lacked some attribute that would say nothing about the individual in front of you.
To say that "most men are this" and "most women are that" is not much different than generalizing about people from the Midwest versus the South. Long ago, I heard a Prairie Home Companion skit to the tune of the Chorale from Beethoven's Ninth about how shallow Midwesterners are. We ask "How are you?" but we really do not want to know. "I'm all right. How's your wife? ".... "She's fine, too." ... My sister-in-law is English. We were visiting them while her sisters were there. My wife and I wondered if it was just us or are they really that rude? "No, they're just English." To use your trichotomy: are they born that way, or is it a natural reaction to being born that way, or is it a cultural reflection of the natural reaction to being born that way? See, it does not work; there is no logic; and the empirical evidence about how cold and distsant the English are, such as it may be, would be disproved at a rugby match.
So, too, with sex and gender.
My favorite counter-example from a college anthropology class is the primitive tribe where the women go out with dragnets and clubs and catch small game. The children old enough to be off the teat but too young to work stay back at camp with the men. It seems that some time "long ago" the men convinced the women that fire is a dangerous thing that only men can tend. So, they stay home with the camp fires and the kiddos. There's a lot of these counter-examples in just about everything that we commonly think differentiates men and women.
Are you prior military? The Marines have a transgendered (female to male) rifleman... and now we are looking at female Army Rangers. It is not just size. In Make Your Bed by Admiral William H. McRaven, the former SEAL commander tells of the competing teams in his class at Coronado, California. The smallest guys were put into a team. The others called them Hobbits. The Hobbits won the competitions nonetheless. So, the fact that "most" men are larger than "most" women is irrelevant in the one place where it would seem be most consequential, as (in the words of Gen. James Mattis) "the battlefield has its own accounting system." And it matters less and less as even the Marines use drones and robots in the field. And personally, I serve with several women far more physically fit than I am. Even though I exceed my minimums, that's about all I do.
And on a related note, my degrees are in criminology. We know from surveys that women write more tickets than men and they have fewer complaints from the public. So, if you wanted to discriminate on the basis of sex when hiring police officers, you should shun men because they cannot do the work of women.
Even the seemingly fundamental physical differences do not stand up as absolutes.
And those outliers aside, we know from Old Testament Biblical scripture that some women just do not have babies. Are they not women? Then what is your definition? It is like the definition of "life." Living things reproduce. That's easy. But crystals are not alive; and mules are.
When it comes to living together and benefiting from civilization, Objectivism teaches a different individualism than does libertarianism. Traditionalist conservatives who are attacted to some aspects of Objectivism argue well that you have a perfect political right to discriminate on the basis of race or gender. We have had those arguments here. The unanswered questions are not about what "most" men or "most" people from Indiana are like, but what you do about it. Because the rational individualist does not engage in self-destructive behavior - despite the libertarian arguments in support of drug addiction - the rational individualist does not discriminate among the persons they meet on irrelevant characteristics.
(Edited by Michael E. Marotta on 2/14, 9:02am)