[nyong]

I agree with what some of the posters have said. It depends on your level of exposure to the people.

We are used to recognize differences based on skin tone, eye color, hair color, mostly because White people have these characteristics on which we can easily recognize differences. Now East Asia (or South Asia or SE Asia or Eastern Africa, etc.) has pretty much the same level of diversity, but we are not trained to recognize those differences. A person who grew up in China could probably tell where another Chinese person comes from based on their appearance. We can't because we're used to observe other features like mentioned above.