Validation of Nietzsche's ideas in more of a modern, scientific context. Thinking about a person's morality as originating from a person's psychology.

What does it mean to scientifically validate Nietzsche's ideas? What invalidated the ideas in the first place? I'm assuming the association with Nazis and Mussolini.

Validating them in the sense of using the ideas as a model to understand our own psychology, and the origins of our moralities. Showing that certain ideas that Nietzsche held around free will and the nature/nurture debate hold up to scientific scrutiny.