First, no commentator in this venue is an leading researcher in sociology or anthropology, so anything said is incredibly weak evidence for your strong claim that researchers / academics "who are currently in [those fields] are more interested in pursuing a political agenda than truth seeking."

FWIW, I recently saw the thesis talks of a few graduands in social psychology, and they seemed to me qualitatively different from those of physicists: in the former, the professor who introduces the graduand to the audience will spew out lots of applause lights (e.g. “Ms So-and-so is going to speak about $topic, which is such a big problem nowadays that affects so many people”), professors will occasionally interrupt the graduand with comments like “yes, this is a great idea, I hope to see more of this in the next years”, and after the talk they will ask stuff like “why did you choose this particular topic” (trying to elicit applause lights from the graduand themselves); in the latter, the introduction will be limited to “Mr So-and-so is going to speak about $topic”, full stop (even when they could in principle mention how graphene is such a revolutionary material or whatever -- they just don't), no-one will interrupt the graduand unless they say something unclear, questions at the end will be strictly technical (or occasionally “what applications can this have”), and there are hardly any applause lights except trivial ones such as “thank you for your attention”.

BTW, while I'm not familiar with linguistics except through the internet, ISTM that it is seen as a hard science (for the purposes of what's being discussed in this subthread) by insiders but as a soft science by most outsiders, and as a result once in a while a non-linguist will be disappointed when a linguist refuses to espouse boo lights about non-standard language usage (e.g.).

Second, you have not stated what evidence you could see that would make you believe the sociological / anthropological theories are true.

Consilience, i.e., independent verification of their claims by people from other fields and few instances of refutations of their claims.

If Omega (who is always right) told you that anthropology is not more politically driven than physics, would you accept anthropological theories?

I would mostly update in the direction of him not being Omega. Now if he made a claim that was at least plausible, like anthropological theories having some political drivers but not enough to overwhelm the science that would be another story.

First, no commentator in this venue is an leading

I wonder how much difference the grammar/typographical error made to perceptions of this comment. For some reason that trivial little 'n' acts like a speed bump/interrupt for my brain and it kicks me out of the flow of the argument.