Good point, I don't think it's exclusively high iq, but I'm not sure about how well of an exceptiom China is currently as they are also experiencing a deceased birthrate (though the gov't had some influence in that) and they also were Communist for so many years which is the hedonist's dream; everything is provided for by the gov't according to one's "needs" not actions (though it's incredibly flawed).
Also the Japanese and South Koreans are also experiencing this problem in a less magnified way, decreased birthrates, less marriages, etc. Though I do agree it's nowhere near where the Europeans are currently.