Ah sorry I did mix you two up.

you said "sex is more like the construct around the biological bits".

Correct, except the construct is not only built around the biological bits, the construct transforms the biological bits. We actively weed out sexes that are not male or female, and in doing this over time we breed humans to meet our desired dichotomy.

Of course I can; humans aren't particularly special, at least not in relevant ways.

Humans are incredibly special. Humans are the only single species mammal. In that sense given the diversity of human ethnicities, humans are the most specialized-unspecialized species in the world (specialized in the sense that the species allows for the vast degrees of ethnic traits to be completely compatible with any human; unspecialized in the sense that we remain neutral enough to adapt to almost any environment and have not biologically chained ourselves to a particular habitat). Humans are the only species that we know of that creates a shared reality of perception (meaning that if I point at something, you know not to look at my finger but look for what I am pointing too; we are able to see our goals, victories, and aspirations as shared with a larger social entity). Humans are the only creature with a cultural paradox (A cultural paradox is where what is prescribed by their tribe often times is detrimental to their survival, but to go against the tribe is equally if not more detrimental.).

Biological classification is useful for organizational purposes, but the categories created are often times severely lacking. In this case, I think humans are so different from most other mammals that it is not useful to use them as an insight into human nature/ the development of the human species.

[Although I am not proud of this, reflecting on your question "why you're presuming social effects are the primary selection pressure," the conclusion I came to was] Because it is the political position I was indoctrinated into. in undergrad anthropology we covered feminism and the idea of sex as a social construct is pretty much the big idea of third wave feminism. It was such a unique and interesting idea that I accepted it into my own ideology pretty readily. However honestly, the counter-arguement that there there are other genetic factors that are more primary is potentially acceptable.

As to your prior

that deviation from normalcy decreases the chances of fertility for that individual, and possibly more importantly, their children.

I would respond that what is normal depends on the in-group of the individual/community defining normalcy. Since people to some degree define their in-group based on the people, symbols, media, and cultures they interact with, I would argue that the process of labeling what is normal is a social construction.

For example, the social rules about men using women's restrooms (and vice versa) are gendered, not sex constructed.

Huh? I remember an Italian female senator making a big fuss when a male-to-female transsexual senator (who hadn't undergone SRS yet at that time, IIRC) used the women's toilet in the senate.

Sorry for the late response, I have been really busy with work.

The variety of gender constructions in our society is the result of a societal objective to perserve a strict dichtomy of sex. Therefore while I would agree that more people are directly assualted with gender constructions, I would add that it is in protection of cultural beliefs about the construction of sex that a wide range of gender constructions are created and implemented. Or in other words, Gender constructions are the means by which constructions of sex are legitimized. Without importance on the later, the former would diminish into obscurity.

To illustrate this I would ask you to think about constructions of age in American society. As of late, there is not nearly as strict a dichotomy between "old" and "young" in American society as there is between "male" and "female." Of course there is still a clearly defined dichotomy (one set by law). But America does not have a multitude of age related norms and customs that would equal the concept of gender for sex. We are not trained to strictly categorize the way old or young people dress. Perhaps 30 years ago there were many hobbies and professions that were normatively bracketed to either old or young (A young person might be ridiculed for drinking prune juice? An old person might be looked down on for being too adamant about video games). However, I feel current American society has become even more accepting of occupational and recreational deviations from these normative age construction. It is generally acceptable for a man in his 40s to like video games, and while a child may be labeled "weird" for drinking prune juice, they are by no means subject to persecution because of it.

Sorry if I was too ambiguous with my language. I highlighted the non-functioning genitalia because it is how I remember the distinction; but both ferms and merms have genital structures unique from hermaphrodites in that they are synthesized with quasi male/female structures. The processes of sex, birth, waste defecation, urination, ejaculation and menstruation are all somewhat different.

If you were looking for different variation in the sorts of things that are normally clustered with "sex", then there are a lot more expressions. There are for instance ambiguous genitalia, unusual chromosonal sex, Aphallia, and especially human protandry.

You are right, I am not an expert on all this stuff and I should not have said “five” in such a definitive way. In general, I have developed the bad habit of writing with too much authority. I apologize for that it is a byproduct of my time debating. I shouldn’t have said “five” in such a definitive way. That said, the point I was trying to make is that the concept of sex is socially constructed, which what you are arguing does not change right?