Ok-- this is an olde question a current pit thread brought up in my head. In it a poster says someone said that you can tell if someone’s “black” (let’s ignore all semantic arguments and genetics arguments about subdivisions of our fine species) by looking at their fingernails. Now, I hadn’t heard this in a long long time but my mother who is of another place and time (she has “theories”) told me the same thing when I was very young-- I’m a light-colored blond person, but she pointed at my fingernails and said “this shows our family had ‘black blood’ in it somewhere back there.” Cool, I thought, but since then (I was a smallish child) it has never made a lick of sense.
So, is having a small lighter semicircle under the nail close to the cuticle a ‘race’ indicator (I guess I mean more typical of one or more particular ethnic or geographical group) or is it basically along the lines of rolling your tongue or detached earlobes or lefthandedness and more or less widely spread throughout all populations? I haven’t obsessively been looking at my acquaintances hands so I’ve no idea how common or uncommon this is.
I’ve never heard this one, so I’m curious. Which was is the presence of small lighter half circles supposed to indicate? Yes or no to “black blood”?
Well, if your mother were right, my thumbs have black blood in them, but not my other fingers.
I’ve never heard this one either. I have light semicircles on my thumbnails, and left middle finger, but not the others. (I believe I had them on other fingers when I was younger.) I’m of Irish-German ancestry, and pretty sure I don’t have any recent African ancestry, unless some Ethiopian was wandering around County Mayo a few hundred years ago.
I would give this one a categorical “no.”
I’ve got them on my thumbs, index fingers and middle fingers, but not on my ring fingers or pinkies. Is there anyone who doesn’t have these at all?
I don’t have any. What a weird theory.
I’ve got white semicircles at the bases of my thumbnails, but none of the other nails have them. I know I am 1/32 Cherokee, FWIW.
I had those circles when I was a kid on all my fingers, and now just on my thumbs.
…Maybe I was black as a child.
Aw, darn, apparently not.
My left fingers have them very faintly, left thumb, nothing. My right hand has what I guess are normal semi-circles on all digits. I’ll leave that to you guys to figure out. 
I have heard this, too, but only from “older” folks, say born in the WWII era and earlier (southeastern US).
Michener’s The Covenant (about South Africa) had a character’s fingernails (and, specifically, the half moons at the base of them) being inspected for clues about her racial background. But even the people who were looking at her fingernails didn’t seem to know what they were looking for.
Did the older folks you heard this from know exactly what about fingernails might indicate black ancestry?
Everybody has half moons on every fingernail. It’s just that some people’s cuticles grow up over them and hide them. If you don’t see them on your fingernails, buy an orange stick and some cuticle cream, follow the directions on the cream, using the orange stick to push back the cuticle and voila - a half moon.
Nope. All I ever heard was “you can tell by looking at the fingernails,” and I don’t recall any further explanation.
My grandmother is a believer in a similar idea (she believes you can use it to figure out what color a black baby will turn out…since black babies are born lighter, and darken with age). It’s not the nails she looks at though, it’s the cuticle.