[Tomisimo]

I think what the innate grammatical rule boils down to is that the subjective, least defining adjectives are farthest away from the noun, while the most defining, most intrinsic, least subjective adjectives are closest to the noun.

So taking as an example, "the nice, smiling American lady", we can see that above all, the lady is an American lady-- being American is a more important piece of information than the fact that she is nice or smiling. Then we have "smiling", which is less important, it is something that can change easier, but it is less subjective than "nice".