Greg Clark's theory says that the lower classes in England failed to reproduce their numbers and were replaced gradually by the children of middle and upper class people. Since they had higher IQs and other parameters, the process produced a harmonious and effective society that brought about the Industrial Revolution. (*)
I found
a Chinese study that evaluated the effect of the brutal replacement of the middle class by the poorest and lowest class as happened after the Communist conquest of China in 1949. Its conclusion is that the social restructuration had lasting effect and the descendants of the pre-1949 middle class never recovered their grandfather's positions. If Clark's theory is correct, the high IQ families should have recovered their status by this time, but they did not.
It would be interesting to study what happened in Taiwan and Hong Kong where this social engineering did not take place, but rich families migrated with their properties and professional privileges. Every Chinese society advanced in these 70 years, yet Taiwan and HK's per capita GNP is more than triple of the mainland.
In comparison, the children and grandchildren of the ruling class in Nazi Germany did recover very fast their high status twenty thirty years after WWII, and the same happened, in Hungary, were the Christian fascist middle class silently recovered its social status in the sixties. Hungarian Jews, that lost all their properties and were enslaved under the fascist regime, raised even faster everywhere they moved. From the paper:
Chinese Communist Revolution was a class-based revolution with peasants as its main supporters. In 1949, the Chinese government soon registered every citizen as belonging to 1 of 3 broad classes according to his or her presumed role in the revolution: “good class” (“red class” revolutionary cadres, revolutionary soldiers, and revolutionary martyrs as well as industrial workers and poor and lower-middle peasants), middle class (middle- and upper-middle peasants, urban routine staff, small businessmen, intellectuals, and professionals), and “bad class” (also called the “black class,” including landlords, rich peasants, capitalists, capitalist roaders, counterrevolutionaries, rightists, and “bad elements,” such as criminals). This classification scheme was largely property based.
One of the most visible and most consequential policies was the distribution of educational resources in favor of good-class children at the expense of bad-class children. Redistribution strategies included rapidly expanding education at all levels, opening special schools for government cadres only, and developing college admission policies that aimed to increase the enrollment of good-class students and restrict the number of bad-class students. More than 60 y have passed since these policies were first implemented. Most grandchildren of the revolutionaries have now completed their educations. A natural question to ask is whether these preferential policies actually succeeded or failed to transform the social stratification order.
That may mean that the pre-Communist social stratification was not based on hereditary advantage like high IQ. Unlike in England and Europe. Or something else.
(*) I linked to The Telegraph because google did not produce even one faithful summary of Clark's thesis, all the references are misleading and untrue. I think there is a serious effort to confuse the people, and the motive is to maintain social harmony. "They" are treating us like violent, slightly moronic children.
Pic source.