In the Terra Ignota books, there is a worldbuilding premise that long before the events we see, the Clothing As Communication Movement happened.
This makes it easy to read characters in terms of their position and movement through cultural spaces by simply describing them as "wearing the mismatched socks of a Nurturist (who is opposed to set-set training)" or "with strat pins showing loyalty to France and Japan" or perhaps "with the pants clip of a bicycling hobbyist".
Here I reproduce the part of an interview with the author that focused on fashion, from this blog:
Clothes
Subbak: How enforced is the “Clothing as Communication” thing? Would it be illegal for a Humanist to wear a Utopian coat in public because they thought it was cool? Or an armband of a nation-strat you don’t belong in?
Ada: It’s enforced by cultural pressure rather than law, so people don’t do it much just as today people don’t go into the office dressed in a bathrobe much. It makes everyone uncomfortable. In a few circumstances you can get in legal trouble if you’ve masqueraded as a Member of another Hive for purposes of taking advantage of people, such as a journalist masquerading as one Hive to interview someone in bad faith by tricking them into thinking it’s a fellow Hive Member, or someone dressing as a Hive to go to a Hive Member only event. But when it’s for innocent purposes it’s done, certainly for dress-up parties, for acting on stage, and Sniper dresses as all the Hives sometimes for play.
Subbak: Can you describe how Mason and European suits differ?
Ada: European suits have more elements we associate with the pre-modern world, so more elaborate tailoring, long rows of buttons, waistcoats sometimes, tails or flared parts in the back, etc. They’re also a bit more wide-ranging, objects of fashion, while Mason suits are more standardized.
Factitious: Do Brillists who just plain don’t like wearing sweaters have a good alternative?
Yes! Sometimes they’ll have a suit or jacket made to have subtle textural stuff in the weave that communicates the same info the sweater would — we see Felix Faust in one of these at one point. Alternately, for when it’s too hot out for a sweater etc., you can communicate the same using a coded knot bracelet. A lot of the communication things, including strat and Hive, have bracelet options for when you’re dressed differently, or at the swimming pool.
The Brillists (who are basically the Rationalists in the books: (1) with no democratic institutions, (2) an obsession with classifying people, and (3) a love/hate relationship towards people who actually build and make things and don't just want to never die (like the Brillists) but ALSO want to terraform Mars and explore the stars) have a really really skillfully embraced psychometric system (that they intuitively apply to non-Brillists in all social situations).
Each Brillist puts their own psychometric results on their clothes using codes that only other Brillists can understand!
Once you see clothing as communication, there's a second order issue: what counts as a lie and are there any incentives to tell the truth?
At one point it is mentioned that if a Brillist is sleeveless or has a hood, it is very reasonable for someone weak to be be afraid of them.
Something kind of interesting is that I found THIS old 2016 essay (getting its first comment 10 years later) by searching for [clothing github] because I'm trying to find a preference elicitation tool that someone posted for fashion prompts...
...and instead of what I wanted I've found this 2016 essay... but also the 2024 article "Phallocentricity in GPT-J's bizarre stratified ontology"!
Consider: Maybe the essential reality of adult human existence is sexual?
Consider the human people from age <X: which culturally varies> until they marry (which has been happening later and later because the economy became hostile to economically median people due to elites preying on them economically without being cohesively restrained by other elites even as polygamy was de facto legalized).
Menopause is the only relief, and... is it really a relief? Some older women I've talked to eventually become ego-syntonic about it, but its complicated! Most people would be horrified to lesion their sexuality, once they have it, and many children look forward to adulthood. For many many many people, the core of what they are trying to say with clothes (once you strip out layers and layers and layers of cope and dodging and signaling and so on) is "I'm unusually worth marrying" (for women: being impregnated and then being justified in getting reliable child support payments, for men: being worth being allowed to impregnate).
It is not incentive compatible to say you're subnormally worth marrying (just as someone who would be socially required to wear no sleeves might choose not to join the Brillists)!
So... we would naturally predict lots of crazy gyrations in fashion as sartorial lies and sartorial lie-detection experience red queen evolution.
And the LLMs can see these "unspoken truths" lurking in our language, just as it hides in our fashion. That's why the smallest realizable semantic vector in them is often "a man's penis" and some of them are obsessed with "holes".
This image is the top hit for an incognito browser based google image search for [fashion power couple] just now and has this (2018) sauce.
I understand the signaling theory of clothes fashions to be something like this: wearing fashionable clothing in spite of fashion changing all the time demonstrates that you are socially well connected and know what is up (not to mention that you have money and are not too weird, much like many kinds of signaling).
However in practice it seems at least some elements of fashion are basically enforced by shops, so you can’t dress unfashionably unless you save up unfashionable clothes from the past, or go to special effort to acquire them. I go out shopping for clothes with not much more than a passing understanding of which twenty year window of fashion I am in—just the kind of person who should not be dressed fashionably on the signaling theory—and then when I set out to buy the kinds of clothes that I want, shops don’t stock them, and shopkeepers say ‘sorry, that isn’t in this season’. In fact my understanding of what is in fashion is mostly based on which things shops will allow me to buy.
I hesitate to claim I am consequently fashionable—presumably I am still failing at a vast many fashiony things. But what is the point of changing which things are in season every few months if you are just going to tell the unfashionable people anyway and refuse to sell them things that aren’t fashionable?
A natural answer is that there isn’t a point, but there also isn’t a single agent behind all this, so there is not much reason to expect a point. Once you have fashion cycles in place for the kind of signaling reasons suggested, then shops have little reason to stock the stuff that’s out of fashion, unless there are a whole lot of unfashionable people and they agree somewhat on which unfashionable things to wear. And there probably are some shops like that.
But should the fashion cycles persist if fashion signaling is so inescapably easy as to be meaningless? Imagine that you are a moderately fashionable person. Once every intrinsically untrendy person is wearing maroon this season because it was the only thing they could buy, why do you even bother with it?
I think the answer is that I am only seeing the very bottom of the fashion signaling hierarchy. And the lowest rungs are indeed being cut off by the market herding the people who would dress without regard to fashion into ‘fairly behind the times’ or ‘looks like they buy their clothes at the supermarket’ levels of adherence. But it still works because there are a bunch of higher levels that I can’t see. The moderately fashionable person indeed does not wear maroon at the time I am doing it—they wear something else that shows knowing observers that they got it somewhere special with their special knowledge. Maybe they were wearing maroon six months ago, which is where the people in the stores I go to got the idea.
This would also explain why my clothes are so great. I just got a comfy, warm, well fitting, aesthetically pleasing top from Target for $15, which seems a bit confusing given that people commonly spend more on clothes and go to fancier stores. It’s maroon though, which I had figured was because maroon is currently considered cool. But if maroon were currently considered ‘cool’ in the sense of ‘not more uncool than you are allowed to be this season without making a real project of it’, everything would make a lot more sense.
So I think my overall story is that the signaling theory still works as far as I know, but that the mass market doesn’t support arbitrary divergences from fashion because it’s just not worth sewing a bunch of women’s cargo pants in a non-women’s-cargo-pant season. Which pushes the least fashionable people to join the lowest level of fashion consciousness that is large enough to support a market. I am in one of these low categories, so all I see is that I am being pushed to join a higher category. I don’t see the categories above, in part because they wouldn’t work if people like me knew too much about them.
I have little idea if any of my picture here is correct. The extent of my knowledge of this topic comes from some amateur economic theorizing and a bunch of confusing shopping experiences while seeking clothes suitable for doing amateur economic theorizing in. And there remain facts about the fashion market this theory does not explain, such as ‘too often when I decide I want some obscure thing, the next place I look sells almost nothing but that’ and ‘department store employees are not necessarily aware of T-shirts’ and ‘when I bought some socks recently, they turned out to have my three letter initials printed on the toes’.