Many years ago ... I was talking to a student writing a Ph. D. on make-up (cosmetics - lipstick, eye shadow, that kind of thing). I remember arguing that perhaps the notion of "make-up" has to be understood in relation to a base line of "body maintenance" and that, over time, the same act can shift from one category to the other - more precisely, that what was once (superfluous) make-up becomes (required) body maintenance.
As a child, in the early 1950s, I once watched an elderly woman feeding the squirrels in a park in Bournemouth. She was a bearded lady - she had a straggly white beard. Even then she must have been eccentric to have not shaved it off; today, she would be extremely eccentric or worse.
The standard for body maintenance for women is now much higher than it was fifty years ago - women, and not just young women, are expected to remove hair from upper lip, chin and so on.
Fifty years ago, body maintenance for men and women did not (I think) include use of deodorants or after shave - though shaving creams used by upper class males were often perfumed and can still be purchased in the right shops.
But men did use hair cream (Brylcreem, Trugel) and the passing of this category of make-up provides a case example of change moving in the opposite direction from the norm: it now seems to us an ill-conceived form of make-up, simply necessitating the use of anti-macassars (as once provided by British Rail).
In contrast, men never used perfume then, though now they do.
Minimum standards have changed. Clothes which once were changed weekly are now changed daily: socks, underpants, vests, shirts. Hair is washed daily, not weekly. Showers are taken daily rather than baths weekly. Teeth are brushed more frequently. All this within the space of fity years.
The standard for self-neglect has consequently shifted. A grubby shirt collar is now enough to signal it in a man.
The minimum standard acceptable at work has also shifted, though at the same time it has become les conformist. It is now more important that you wash your hair than that you have a short back and sides.
Very soon, the stink of cheap tobacco hanging round someone will lead to them being considered unemployable.
You get the idea. It's easy to expand on this - and even write a jolly interesting Ph. D. If the focus was on standards of body maintenance in Great Britain, the title could perhaps be From Godliness to Cleanliness.