Did a Jeeves search…
Came up with most of the answers mentioned above.
Sign of wealth,
That your labor days are behind you,
Neglect,
Keyboard striking reasons,
To pierce for jewelry,
Cocaine.
Here are the results of the search.
A Google search produced some interesting ones: that Picasso kept a long little fingernail for mixing paints, and (a probable explanation for the Delany observation) that Turkish men commonly keep such a nail for opening cigarette wrappers.
My grandfather has a long fingernail on his pinky. But he is from Europe, is not by any means a hippy, does not do drugs, is not a pimp, does not smoke, and does not care at all about fashion (in fact, he doesn’t even know what the post 1950’s fashions were/are). Not to mention, the fact that he keeps it clean and does not use it to clean an ear or a nostril.
I once met a guy who kept one nail long as an anger management technique. When he made a fist, the nail would remind him to reconsider his actions before striking someone.
Haha
That’s the best explanation so far!