> do you really think you can objectively evaluate the truth of these claims without bias?
Yes, more or less, just as many kinds of professionals are required to do the same. But regardless, my entire point is that the truth of these claims is the least important thing about them, just as the interesting question about a wager between two college students of whether a vagrant would shit his pants or not when they set him on fire is not which of them was right.
> I assume you mean the motivation is some sort of collectivist hatred or other negative feeling
I did not study psychology but history, and I'm not interested in feelings but in the distribution of power. Yes, the motivation is to justify and perpetuate a distribution of power that's favorable to the groups where those ideas are found.
> In that case, it's pretty clear that you intend this to be a mere ad-hominem attack. You simply refuse to acknowledge the possibility that a person might hold certain positive beliefs without also holding certain normative beliefs.
Not at all. When discussing the history of ideas we do not attempt to track every single person's motivations, just as I don't suppose you "refuse to acknowledge the possibility" of some black woman being smarter than some Asian man. Your beliefs -- as I hope you know -- are not only not unique at this point in time, they echo almost precisely very old and well studied ones, and thus can be and indeed have been discussed in general without attributing anything to you personally. Even in proper science (leaving aside the question of whether a certain strain of scientific racism qualifies as such or not), researchers often discuss why they're interested in a specific question (and need to justify the importance of their research in order receive grants). So the question of what motivates certain people to be interested in studying and publicly writing about any scientific topic is not only reasonable and pertinent, but a fairly common one. Even on a personal level, a scientist often needs to answer it to herself and to others.
Also, I am absolutely not attacking you, but merely pointing out that the name of the school of thought your beliefs (in this context) belong to is scientific racism. Perhaps now that you know what your philosophy is called, you can more easily find academic discussions about it if you are interested in learning more. But just as I wouldn't be able to fairly say, "people here are call me names like billionaire", after telling them I have billions in the bank regardless of my personal feelings towards the name, I don't think you get to say that people "call you racist" when it is you who present yourself as such (and not in any subtle way, or one that's open to interpretation), even though it turns out that you don't like the title.