Interesting... 
While biological causality is extremely difficult to prove and this does not prove it, it suggests that the communist view of wealth and wealth creation is simply wrong.
Moreover, many elites were educated in expensive private schools and universities prior to the founding of PRC in 1949. Although the "cancel culture" during the Cultural Revolution halted school education and banned many "capitalist" books, the children of these elites can always find books to read under the guidance or influence of their parents.
@snoopes
That's quite possibly true however something that's impossible to account for as there are no numbers on something done in secrecy. However I don't think it matters as much as the communist regime focused on providing education to the working class and made it much easier to get accepted if you had a working class background.
Contrary to the elite education before 1949, the popular education adopted by the Comm gov rolled out massively, but the quality varied drastically. In the poor rural areas, teachers were so lacking that some schools were run by farmers. The huge waves of young urban students "going up to the mountains and down to the countryside" from 1968 to 1972 brought the much needed teaching staff for rural schools, even though they were just teenager kids just completing 9 years of education.
Overall, the rich parents had access to much better educational resources prior to 1949. During the Cultural Revolution, even though kids of such parents could not be enrolled in colleges, many of them had been reading avidly in their spare time (secretly, according to many memoirs). In 1977, the first year when college matriculation exams resumed, those ppl were on a levelled playing field with other students, and many of them outperformed children of poor farmers.
@matrix
Indeed, the peasant or working class background was a great competitive edge in college enrollment and access to many resources and career opportunities during that period. As the reovlutionary saying goes, "three generations of poor peasants are proof of upright roots and red seedlings." The gov extolled the heritage of poverty, maybe in a drastic move to revert or even redress the pre-revolutionary class distinction. But few of them were well educated.