How much truth is there to the idea that there are identifiable physical differences between Japanese people, Chinese people, Korean people, etc.? And if there is none, why is the idea that there is so widespread in East Asia?

Let's take this from another direction. Are you asserting that there are no discernible differences among people of "Asian" phenotype?

Among people of other broad geographically defined phenotypes it's often possible to differentiate internal sub-groups. Many people from eastern Europe (i.e., "Slavic") exhibit features that are more similar to each other than they are to folks from western Europe (say, "Celtic / Germanic").

These are not absolutes. People from different populations have always intermixed. Human variation across the world is a continuum.

Among people from Africa, we see similar variation. Same with the Americas. And elsewhere.

You can't draw hard boundaries around these things, but there's no reason that-- if we can observe such variation within our own sets of phenotypic traits-- people from other regions shouldn't be able to see similar variation.

So with a likely margin of error, I don't see it as particularly earthshattering that people from Asia can distinguish-- to some degree, at any rate-- between different expressions of certain traits that tend to cluster in different parts of the continent (and which, consequently, have linguistic and cultural boundaries, and have eventually led to national boundaries being drawn around them).

Your friend is a good example of why these things are not easy to define, and why hard and fast rules don't really work very well for this. But it's not racist or bigoted to note geographically-defined or moderated differences in the expression of various phenotypic traits among large groups of people.

/r/AskAnthropology Thread