Without agreeing with the stereotype that scientists are supposed to be smart¹, yeah this is something that worries me. Be it naziism, slavery, racism the way that it was considered normal and legal when my grandparents were alive: there are so many things about which I wonder how large groups (not just a few outliers) can be convinced to believe it.

How do I know what I'm doing in life is right? By what mechanism could I ensure that I believe someone who tells me that Jews aren't the cause of all evil if I lived in ~1940 Germany? What makes people increasingly vote for racist parties since covid? The average person hasn't gotten any smarter or dumber in many thousands of years; evolution is not that fast. At best, genes might be expressed differently based on environmental factors, but I'm not aware that this is a factor for the aforementioned inhumane beliefs. How "scientists" (or anyone) could believe this is a really good question, sadly

Of course, this is ignoring the group that did fight against the nazi regime and/or beliefs. This is just about the (sufficiently large) group that could be convinced to work towards inhumane treatment or even genocide

¹ we can all do amazing things when we have the right idea in the right situation with the means to execute it. Of course, good ideas occur to a smarter person more frequently, and they might be inclined to become scientists because it's an environment seemingly meant for working on new ideas, but that doesn't mean everyone there is per se smart. Lots of people are only topically smart (not to be confused with topical knowledge: I scored both top % and bottom % depending on which part of the iq test you looked at, so that's not about knowledge but about abilities. Many people think I'm smart, but I think they mainly notice the parts where I'm unusually good rather than the 'boring' parts where I perform normally or below average, or they attribute it to laziness)