After I adopted the language of the new age for transgender issues, I posted a discussion whose conclusion was that sports leagues should be renamed "male" and "female".
Today I'm going to discuss locker rooms.
Locker rooms are actually harder than sports leagues. In the case of sports leagues, it is clear that the segregation of the leagues is as a result of sex, rather than gender. Therefore, the names should reflect that.
In the case of locker rooms, or any other area where the issue is either privacy or its close cousin, modesty, you have to first figure out where that sense of "modesty" comes from. Unfortunately, that's not as easy as we might wish. Why is it that people generally want to keep their clothes on around the opposite sex, unless of course, they are deliberately removing them in order to engage in sexual activity? And is it the opposite sex that they want to conceal their bodies from, or is it the opposite gender?
Some people think modesty is a purely social phenomenon. We only wish to remain clothed because society tells us we ought to. If that's the case, the best solution would be to get rid of segregated facilities altogether. If society is creating anxiety for people, society ought to stop.
However, there isn't a lot of demand for that, which suggests it is more than a social phenomenon. All around the world, segregation exists, except in rather specific and narrowly defined circumstances. Some societies allow more nudity around the opposite sex, or gender, than others, but there is no society anywhere where nudity of adult females in the presence of adult males, or vice versa, is considered normal. Either it doesn't happen at all, except for married couples of course, or there are strict conventions around it, either in the form of actual regulations that limit behavior to certain areas, or social conventions such as might occur among a group of friends playing strip poker.
I don't think it is a purely social phenomenon.
Human beings have a trait that makes them not quite unique among animals, but it is very rare. We copulate at times when there is no chance of fertilization. Also, in most animals, the female has obvservable physical or chemical (scent, primarily) changes that signal her fertile times, and mating behavior in males is triggered by those changes.
We aren't like that. One strategy that would work for such an animal would be to mate darned near all the time with anyone available, but we don't do that either. We tend to be at least somewhat monogamous, although often time limited. And on top of that, the females seem to be more selective about mating than the males.
In order to make all that work, from an evolutionary perspective, we have to have behavioral cues that signal mating readiness. I believe that removing clothing is one such signal. I believe that humans signal sexual availability by, among other things, taking off their clothes. I believe this behavior is instinctive.
I don't know whether it is literally instinctive, as in this is evolved behavior from 5,000 generations of clothes wearing, or if the general concept of a sexual signal is instinctive, and society consistently labels nudity as one of those signals. Either way, I think there is a deeply held feeling that nudity in the presence of potential mates is a powerful signal of sexual receptiveness. "Modesty" is primarily about avoiding sending signals that one does not want to send.
Ok, my posts sometimes get long, and I could go on for another page, but I won't. I'm sure there will be time to elaborate, so I'll cut to the chase.
The designation of a possible mate is based on sex, not gender, at least at an instinctive level and for the majority of humans. Therefore, the places where one becomes naked should be segregated by sex, not gender, in order to avoid sending the wrong signals, i.e. to appeal to the sense of modesty.
And since the segregation is based on sex, not gender, the signs should be changed to read "male" and "female".
No doubt this will not be universally accepted, but I don't have to write a book, and you don't ahve time to read one. Maybe, together, we'll write one through dialog on the subject.
(It occurs to me that one topic I missed entirely was modesty toward everyone including same sex, resulting in wishes for completely private facilities where one is exposed to no one. That's an important topic. The short issue is that would indeed be better, but might not always be an option. Later.)
On the other hand... you want to do a medical study on children where there is no control group at all,