That's funny, I had a similar reaction. When I hear the word "groom" I immediately think of, well, body hair, or, like dog grooming, or something.
Do you mean fashion? Are you trying to figure out whether fashions are more formal or casual at certain time periods? My observation has been that people are more casual during economic downturns probably because lots of people are unemployed. They tend to dress more at the beginning of recoveries, probably because lots of people have new jobs and folks to impress, and more money to spend on clothes. At the end of long booms, however, people get casual again because they become more complacent/burnt out on work and don't feel compelled to impress anyone. Is that the sort of thing that you're getting at? I guess applied to turnings, Late Awakenings, Unravellings and early Crises are casual dress times and late Crises, Highs and Early Awakenings are formal dress times. Let's face it, though, we are hardly a "dress to impress" culture. There's a reason why Europeans think we have no style.