Earlier quoted context omitted.
A brutal truth is that wealthy, upper class people have resources for training their kids that legitimately better prepare them for academic success than poorer kids. The rich, smart kids in this example were Jews.
In USSR, nobody was rich.
Despite Soviet propaganda to the contrary, social class continued to exist in the USSR.
At the top of the class hierarchy, were senior party officials and their families.
Next rung down were university-educated professionals (doctors, engineers, scientists, etc)
Then came skilled factory workers, etc
Unskilled labourers were near the bottom of the Soviet class hierarchy