These people weren't 'scientists,' they were just scientists. There's a tendency to think of scientific racism as a product of cranks. To think of the horrible, slightly comic stuff like physiognomy. The fact is, scientific racism was supported by the vast majority of scientists, including the very best thinkers of the eighteenth and nineteenth century. It's like the patriarchy: you don't need to be stupid or irrational to be a misogynist, you just need to be unwilling to examine the hateful premise that underlies your entire way of thinking.
This is important because scientific racism could not be 'disproved' and we know this because it wasn't. If the evidence didn't fit, it was ignored.
The scientific method is not a noble path that, adhered to rigorously, leads to truth. It is walked by people, and their unexamined preconceptions shape the outcome.
This sums it up fairly well, in my opinion. The PBS doc
The Eugenics Crusade (which I have yet to watch in full even though it's on Prime because I either squick out when they show a bunch of flies in a jar moving around or fall asleep early on)goes into detail about this as well, though it's specifically on the development of eugenics rather than scientific racism as a whole.
What do you mean by this?
So this was a both a joking comment (in a black humor sort of way, I suppose) and a serious one because as far as I know, no one's really explored something like it in an alt history timeline. But anyway,
Lamarckism (named after French biologist
Jean-Baptiste Lamarck, who inspired these ideas though he's incorrectly viewed as originating them), also called
inheritance of acquired characteristics or
soft inheritance, is essentially the belief that organisms can pass on physical characteristics that they acquired through use or disuse in their lifetime to their offspring. Mind you, this is a vast oversimplification of the theory because I'm not an expert and only have a vague understanding of the concept. Basically, if a parent is incredibly skilled in something, that will then be passed on to their child, and so on and so forth. Darwin took some of Lamarck's theory while developing his own theories while rejecting other aspects.
What I'm saying, in a slightly flippant manner, is that I'd be fascinated by a timeline in which scientific racism develops along Lamarckist lines. For example, in such a timeline, a belief might be that "Oh, [insert ethnic/racial/cultural group here] are viewed as lazy? Clearly, it's because their ancestors were lazy too and refused to be active! Therefore, they're inferior to our group as a whole for not taking the effort over generations to improve their group!" It's a concept that I think could lead to some very interesting scenarios and beliefs, not to mention the effects it would have on the 20th century.