Is there specific text to that effect in ARG? (And if so, can you quote it?) My understanding from before was that they specifically didn't, but it was definitely unclear.
For the same reason that they can't select favored class options from humans and/or elves/orcs, I believe that the answer is that they cannot take them. If a favored class option isn't an effect, an archetype most assuredly isn't either.
I am looking into it a bit more carefully regarding the feats aspect, as Racial Heritage does say that feats count as an effect.
In any case, this question is asked often enough that may as well FAQ it.