I'd have to modify my previous post, then: "What I think is most interesting about D-K is how it is referred to as universal, as an aspect of human psychology in general, but in fact the original studies were done in America on American college students".

As far as I can tell, TFA does not seem claim that there isn't a cultural dimension to D-K, just that we don't know what it is because no studies are cited. I would still say that it doubtful that the studies on Cornell students generalize to the entire population of the world when it comes to these things...