all documentaries have a bias. Anything created by humans will have one. The question is more whether the bias aligns with our beliefs or challenges them. There are a lot of great documentaries in the world. The ones talking about history must be taken with a grain of salt, though. We’ve done a lot of awful things as a species, but we’ve also done a lot of good. Some documentaries are presented in a manner to push an agenda, and these are easy to identify for their over-the-top presentation of “questions” passed off as though they’re fact. Some documentaries are presented in a manner respectful of the people who lived through the events. Some documentaries are works of pure fiction. As with anything, we must always be vigilant to see what is real and what is perceived.