[philwelch]

> Whereas racial categories like these are socially constructed, and do not correspond all that well with genetic population groupings.

If you look at genetic population groupings, the gap between populations that the layman would identify as "black" and "white" is as wide as the Sahara Desert. Literally so, if you put these population groupings on a map.

It's true that, if you look at New World, non-indigenous populations, things get more complicated. But genetic populations still correlate very highly with geography and ethnicity. The layman'a notion of "blackness" or "whiteness" may be flawed, but it's not completely incoherent.