My 10cents :
1. I doubt, too, that these NK folks have the highest IQ on the planet which they are so eager to destroy. Who made such measurements, I wonder. All those Kims would never allow such "imperialistic tricks" to be played with their slaves (well, comrades).
2. IQ itself does not mean much in terms of economic and social development. These are just tests, while the cognitive aspect as well as creativity are not addressed. E.g. we see many brilliant entrepreneurs in US (that drive the economy,) and not all of them, I assume, do have highest IQ in these tests.
3. I think we all know some people around us who are quite knowledgeable, have read megatons of books, but are losers in professional and everyday life.