The entire premise of the New Soviet Man was a sort of eugenics because they were disappointed that people didn't seem to be adjusting well to the new socialist order (wow imagine that) so they wanted to engineer their citizens to be fit for the new regime. Herbert Marcuse even builds off this idea with his concept of the New Sensibility where they actively want to make people crazy so that they are unfit for the current system and become revolutionary. There's a very eugenics heavy portion of this where they want to essentially exterminate all people who are capable of living in a non Liberated, capitalist environment so that over time it is biologically impossible for men to live in any other way but under communism. Truly nasty stuff. Also this mythology that socialism and communism don't have a racialist and nationalist element needs to be dispelled. The North Koreans are basically taught that they are the pure and chosen race thanks to the Leader and so on. The soviets sneered at non-Russians and Stalin was planning on Jewish pogroms before his death. The list just goes on and on