How dangerous are black bears relative to brown/grizzly bears?

[Paul F.]

Don't corner them, and don't threaten (or look like you're threatening) their cubs.... otherwise, you can yell at them and they'll run away.
They're not brave, and not terribly dangerous - unless they're backed into a corner, you threaten their cubs, or you surprise them (and they feel cornered).

At least, their California cousins are that way.

I mean, I wouldn't want to try picking a fight with one on purpose to see if he runs, but, I've scared a number of them off when I lived more in the country than I do now.