Of course objective reality is not effected by belief systems. But science is not perfectly reflective of objective reality precisely because of the belief system of each observer.
Yeah, that's what the feminists and all the other "culture wars" types would have you believe. It's wrong, though. The science doesn't change, no matter what or who the observer is. How they choose to INTERPRET that data is, to some extent affected by the belief system. There IS an objective reality, and science measures it.