The opposite extreme -- belief in "tabula rasa", and how biology doesn't matter for the New Soviet Man -- was also used in the history, also with bad results.

The opposite extreme -- belief in "tabula rasa", and how biology doesn't matter for the New Soviet Man -- was also used in the history, also with bad results. (And similarly, this doesn't prove that everything is genetic. You can't get science by merely doing the opposite of other people's prejudices.) The belief that nothing is genetic can also be used to oppress people. For example, you can dismiss highly intelligent people from poor families by insisting that high intelligence doesn't really exist and everything comes from universities, and then pointing out how poor people usually don't come from the best universities. Any kind of incorrect belief can be strategically used to hurt someone.