[matt4077]

You are getting awfully close to eugenics. That points not only at the moral problem with your willingness to sort human life into desirable/undesirable. It also offers a clue as to the accuracy of this mechanism: If these fascists one hundred years ago were making the exact same prediction you are making, and yet the world today is not overrun by these supposedly reproduction-happy Untermenschen... then maybe it just doesn't work like that?

More specifically: this fear is based on observed heritability of traits like intelligence, and also social status etc. While these are indeed hereditary, they quickly dissipate when considering more than a single generation.