Oh I don't know Lew! I thionk they are different mainly because they are teenagers on film transported to a new country with a different (very different) family.
If they had grown up there? If they stayed there from now permanantly?
I think they would be resentment and anger about sexuality, independence, freedom of thought and actions.
They are not parents I would emulate despite (and perhaps because of) their extraordinarily well contained children.
I do think they are not completely nutty though, they have said some lovely kind things to those teens.