[yowlingcat]

There's some nuance to the differences -- think about the terms "old money" vs "new money" -- the fact that people even came up with those terms tells you a bit more about the hierarchy. I think it's an interesting thought exercise to continue why it's more formalized. Perhaps some of the explanation could be derived from the relative age -- present Indian society is about 10x older than present American society, in which native societies were in large part wiped out by disease and subsequent colonial settlement, the latter of which is only ~400 years old.