I think that'sjust for wetlanders. I'm pretty sure Karede or Egeannin or someone like that mentions distinctions, just as they also descibe a wide range of complexions (as opposed to the BWB's persistant Oriental look).

Aiel. They're taller, and have better prenatal care, both of which suggests strong sons. Also domestic violence is not only permitted, but they fight back like people with guts, instead of whining about it. And an Aiel wife comes with a house.

Amadicia any day. The ruling class is kept in its place by an egalitarian meritocracy, and you don't have to pay to live or work in buildings designed for exterior aesthetics. Imagine what a pain in the ass it must be to run a business from a shop designed to look like some stupid nature scene that might totally clash with the image you are trying to project, and you have no choice other than send for imported workmen from hundreds of miles away, or suffer. You know they aren't going to be too keen on casual renovations or putting on additions that make your giant stone animal look like it has a box growing out of its ass. It makes a pretty sight for tourists (in a time where tourism is a non-viable industry), but that kind of place would be a pain in the ass for trying to fit normal lives around.