I have a colleague who shares a skeptical temperament with me, so we get on quite well. But he's more inclined to be skeptical of every source than I am. And this leads him towards paranoia and conspiracy thinking from time to time. Sometimes I see an odd phenomenon with him where the more obscure the source of information, the less skepticism it attracts, as long as the story challenges some formerly established narrative. Eventually it becomes a kind of inverse pyramid of justification: the impact of the single latest and most dramatic challenge overshadows the credibility of sources that have accumulated a reputation or cited their evidence, and the thrill of imagination overwhelms evidentiary reasoning.

For the most part we have some pretty good conversations, but occasionally he goes way out there. I have heard him say the moon landings were faked and vaccines may cause autism, and if I point out the readily available debunking evidence, I get a shrug and "I'm not sure about that." (To be fair, he hasn't said the first of these for a while, and I stopped asking about the second.)

One other thing I have noticed is that as we get older he becomes more reasonable and less certain of conspiracies. And I can say "you're being paranoid" and he doesn't reject me as one of "them". At the same time I find myself less certain of most things. I think this is a nice way for us to grow up.