> Before ww2, the scientific consensus was that we evolved in a branching species rich manner, same as any other animal.
This was a time referred to as the "nadir of race relations" in the US, and if you read the output about humans as a species from that period, you'd be a lot less impressed. It's all out of copyright and a lot is available online. It's not what most of us would look at as science, now. It's more like mythmaking.
Also, take a look at the history of eugenics, which was seen in the years before World War II as a legitimate and noble scientific goal - to improve the human species by the application of science and engineering, no more immoral than breeding hardy tomatoes or fast horses. Many countries that joined the war on the side of the Allies had significant scientific, governmental, and public support for eugenics (the US and the UK had a Eugenics Society, Canada had provincial Eugenics Boards in Alberta and British Columbia, etc.). Neutral Sweden had an active eugenic sterilization program.
So, the "scientific consensus" of that era involved a number of scientists from many countries who agreed with policies and goals that, in retrospect, we now see as not only politically partisan but also specifically aligned with Nazi political ends.
Yes, a lot of scientists believed in hateful pseudoscience like scientific racism, eugenics and phrenology.
Your argument is a very common one but very flawed. Antisemitism, ultranationalism and eugenics aren't bad because the Nazis did it. It's exactly the other way round!
Eugenics are just as flawed and criminal when a Swedish doctor or a British politician advocate for it.
I think you're misunderstanding my point - I'm saying that eugenics was bad at the time, even before the Nazis implemented it at horrifying scale, but the scientific consensus of the time was that eugenics was a perfectly reasonable thing to work on, and therefore we should not trust the scientific consensus of the time.
If the scientists of that era said that certain humans were an inferior species to Homo sapiens, and the scientists after World War II said that's not true, we shouldn't assume that the pre-war view was pure untainted science and the post-war one was the result of overcorrecting for political/moral reasons - we should consider the possibility that the pre-war scientific consensus was tainted by political/moral views that we now rightly reject.
> This was a time referred to as the "nadir of race relations" in the US,
Its incredible how little people know about the period in American history between the end of Reconstruction and the start of WWII beyond just: "WWI", "Market Crash", "Great Depression".
Following one theme: Nadir of race relations, Red Summer of 1919, and Great Migration (one of the largest movements of people in history).
It makes it so much more difficult to have an objective discussion about the past simply because people are unaware of it, or simply understand it at a very high / hand-wavy level. "Some bad stuff happened then eventually it stopped."
This was a time referred to as the "nadir of race relations" in the US, and if you read the output about humans as a species from that period, you'd be a lot less impressed. It's all out of copyright and a lot is available online. It's not what most of us would look at as science, now. It's more like mythmaking.