To some extent, its physiological. There is a physical pleasure that comes from “believing” things even when we don’t have evidence for them. “Believing” in things creates a dopamine cycle. Even further, some people are psychologically pre-disposed.

Look at how cults and relgions function: secret knowledge, in-group/ out-group selection, ‘leaders’ who protect or are connected to some “other”, it goes on and on.

We’re monkeys who are hard-wired to find patterns, could be useful. We tell ourselves stories that are “convincing” to believe in these patterns. Our brains give us a pleasurable “bump” when we find one, even if its objectively wrong or easily dismissed by evidence. It takes substantial time and discipline to untrain yourself from this, and humans get extreme discomfort from “not knowing” things. We hate that. We’d rather a wrong knowing than confidence in our “not knowing”. And its not just that we don’t like not knowing; its physically painful. And then there are some of us that are more subject to these forces than others, and because of how self-selection works in online communities, these tendencies are allowed to exacerbate.

We’re really starting on the back-foot when it comes to the “truth” as humans.