I only recently learned that most peoples beliefs are not "factual beliefs". Since most of mine are, I thought that's how other people work. I think Popper may have made the same mistake by assuming "correctness" is always the primary value a belief offers.
The other kind of beliefs are "Symbolic beliefs." Symbolic beliefs are not held because they are true, or because they are useful on their own. They're held because they signal that you belong to the tribe. They are similar to the "Alief", which is an automatic unequestioned belief. Most Symbolic beliefs are aliefs, but not all.
Since learning about this I've been trying to identify my own aliefs and symbolic beliefs and question them. It turns out I have more than I'd realized. We probably all do.
> I only recently learned that most peoples beliefs are not "factual beliefs".
I think this greatly underestimates the number of completely mundane, innocuous factual beliefs that everyone, or at least everyone who is able to get through their lives without serious mishap for any length of time, has to have. For anyone in that position, most of their beliefs have to be factual beliefs, and have to be true at least to a good enough approximation to allow them to function. We tend to ignore such beliefs in discussions like this, but that doesn't mean they aren't there.