#2 tw: It depends on how much of Chinese history you believe. I suspect large parts of their population are either only of part-Han descent or of mostly non-Han descent, and mostly assimilated to the dominant Han culture.
But being descended from pastoral groups like Mongolians, or Manchurians, or Tibetans or even groups from India and Nepal that we don't know much about... they're a lot less lactose-intolerant.
In the 19th century, when China was a backwards backwater, this wasn't too much of a challenge to social stability.
Now though, China is a bit more developed, confucianism and neo-confucianism and exam-confucianism are all starting to regenerate, and any old peasant (and not really one of the "right" people) can go down to the store and buy a 10-15 IQ point boost for their kids on top of the one they'll get for not growing up starving to death in the Great Leap Forward (which itself is probably something like 15-20).
And I wonder to myself, is that the 'problem' all the milk-poisoning is supposed to solve? |