I wouldn't be positive about that either. It could be that both are true, and create a virtuous cycle.

Or it could be that neither is true, and it's really that both characteristics are engendered by having a curious temperament.

FWIW, I'm not sure that a curious temperament is materially different from intellectual humility.

I think curiosity implies intellectual humility but the converse is not necessarily true.

I think intellectual humility without curiosity is a form (or symptom) of depression.

Why do you think so? I've met plenty of people who lead a simple life and are fine with knowing they don't know much, especially in more traditional communities, where superfluous knowledge isn't valued.

Sure, but I just want to note I never made the claim it was the case - I was just offering one possible alternative to what OP claimed.