A very good point. in addition to your point, we are all intensely tribal as it was very necessary for us to recognize people who are the same and people who are different. Before living in Southeast Asia, all east and Southeast Asians look pretty much the same to me. Now, with a high degree of accuracy, I can distinguish not only between Han Chinese and Thai (it is easy), I can tell a Maeo from an Akha or Karen. From facial distinctions, I can tell the region a person comes from and very clearly distinguish a Burmese from a Lao from a Khmer.
It is fascinating to me and I imagine people in America could, at one time at least, distinguish ethnic background just by look (Irish from Swede, from German) with equal precision.
When I got off the plane in TSN in 1968 all those Orientals looked alike.When I got off the plane in SF in 1970, all those roundeyes looked remarkably alike. The first, I expected. The second was kind of a shock.