This is literally the approach taken by the authors of the
WSJ op-ed.
Ok, that's nice.
There's two sex cells in human DNA, I'll set aside a dozen or so caveats and say I understand the meaning of that for this illustration.
Does that mean only two sexual identities exist?
Two very predominant sexes exist, I'll grant you that.
We gave them labels and they are "The Two Sexes."
Then there's those with "ambiguous" sexual characteristics. Very few in number, granted. Still seeing only two
types of sex cells, yes. Perhaps more than two present, though, odd. Also a number of outlier variations on those that are otherwise typical. So kind of a whole broad mixture of different ambiguous possibilities and each type being seen in vanishingly small amounts.
All of those people, they're "intersex."
They "don't have a sex."
Why not?
Because there are two sexes.
We came up with that. Ourselves. Classifying and conceptualizing of them that way.
Referring to that construct being predominantly held isn't really an argument to keep it that way.
The main tag line premise of the study says:
"No third type of sex cell exists in humans, and therefore
there is no sex 'spectrum' or additional sexes beyond male and female. Sex is binary."
Observation seems to show that there is a spectrum of many different variations of physiology and biology that result in a person who does not fall into one of the two categories we have chosen to call "the two sexes." The authors refer to persons who do fall into those categories "unambiguous." What if we move the number of traits that do or don't line up around some? Be stricter or looser with what is and isn't one of "the two sexes" and "intersex." This study could say whatever it wants about the matter, I guess.
But "only 2 sex cells = only 2 sexes" fails on observation if their own definition of sexes still leaves 0.2% unaccounted for. That we call two largely typical outcomes "the sexes" and all other outcomes "flubitty-flarble" seems to be a distinction without a difference.
And so this "study" kinda means nothing to me.
Also kinda why I'm a bit irked about all the "but science says...!" around right now.
Science says try to falsify science. Science says "real close, buuuuut..." has an explanation. Science says learn how to phrase a problem without already embedding an outcome into it.