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.
Personally, I consider "belief" from a behavioral perspective: belief is the model of reality one actually operates from.
For example, when I walk on my kitchen floor, I don't have to tell myself: "the floor is structurally sound, it's safe to walk on it." I just walk.
The fact that I just walk can be used to infer an infinite number of implied bleiefs that I've never verbalized until this moment. For example, I believe that:
1. The floor can support my weight.
2. The tiles aren't made of toxic materials.
3. I don't pay $$ by the step.
4. Walking on the floor doesn't cause my wife pain.
5. The floor isn't lava.
To refine my definition: a belief is that which systematically and implicitly guides my expectations, reactions, choices, etc.
In her glass skywalk example, Gendler lays out the definitions roughly so:
1. "I know this skywalk is sturdy and safe" = Belief
2. The hesitancy to cross the skywalk = Alief
But to me:
1. "I know this skywalk is sturdy and safe" = knowledge
2. Hesitancy to cross it = actual belief.
That's why in my vocavbulary it's perfectly fine to say: "I know it. But I don't believe it."
Similarly, if someone says, "I totally believe that planes are safe, but I'm terrified of flying", then I will think to myself: "nope; you totally don't believe that planes are safe."