I still troll Reddit when I'm bored sometimes, mostly by posting bad information then using logical fallacies to argue with confidence. You know, old school trolling where you just try to see how stupid you can act while getting away with it.
What I've noticed is that when I do this in any other community, people will identify it as a joke and laugh (or see it as outright trolling, which it is, and dismiss it). Reddit is the only place where users consistently think I'm serious and write out multiple paragraphs explaining why I'm wrong, then do it again when I give a blatantly useless retort like "everyone I know agrees with me, though."
Considering Reddit is, once again, the only place that reacts this way to me has given me firsthand experience that yes, these people are not only dumb, but they also are desperate to prove they are not. It is a profoundly insular community despite its size.