The men in the link below were involved in an Adult Swim Ad Hoax involving Mooninites and what seemed to be homemade bombs (but were actually lite brites - read about it here). Their lawyer advised them not to talk about the case, so their press conference mostly centered around haircuts, particularly from the 1970’s. Enjoy.
http://wbztv.com/video/?id=28369@wbz.dayport.com
I’d like to address some of the points/questions they brought up, and answer them as best I can.
1. Was the greased-up look popularized first in the 60’s or the 20’s?
My opinion would be that the style they are referring to was probably most popular in the 50’s, actually, in the era of “the greasers” and makes me think of the book The Outsiders. The “Dapper Dan” type of hair grease does date back earlier, however, so I think that their conclusion that the look originated in the 1920’s is probably correct.
2. Did the Beatles’ hairstyle continue into the 70’s?
Yes and no. I imagine that in parts of the country, the style continued to be popular, and really, the Beatles’ style evolved into the 70’s. So I would say that mostly no, but you could still be cool and have an updated Beatles ‘do in the 70’s.
early beatles:

(source: allposters.com)
beatles in 1970:

(source: larsholst.info)
3. When did hippie long hair start?
Although it is impossible to really say for certain the exact moment the long hair trend started, I think it’s safe to say that hippies were pretty common by 1965, and that long hair was a trend by The Summer of Love in 1967. Since it takes about 2 years for short hair to grow past the shoulders to suitable hippie length, I would say a fair estimate would be 1965 or earlier for the beginning of the hippie long hair trend.
4. What about 80’s hair band hair - Was it an overcompensation, with people living fast and loose?
The 80’s certainly was a time of living large and extravagantly. Clothes were colorful and flamboyant and so was the hair. However, since the question is worded rather loosely, it’s hard for me to say what hair bands might have been overcompensating for. We can just use our imaginations, yes?
I hope this clears up some of the very important questions raised in this press conference and I would love to answer any more you all might have, to the best of my ability.
Beth