Actually, black bears rarely defend young (It's an evolutionary thing that I've explained elsewhere), most food defensive attacks s are acclimated bears ("Fed bear is a dead bear"). Most fatalities are predatory attacks by male black bears (rather than grizzlies)
I'm surprised, but that's actually right. Predatory bears are the problem bears. You can typically pick up on bears that are predatory, they give signals that you can pick up on. They obviously look for opportunities to get to you. Sometimes they will try to get ahead. Overall what they are doing is sizing you up. Fairly rare behavior, only ran into one, and we had a 44 mag with us, once we picked up on what was going on.
We had a well-known "trash bear" that was outside of my study area but hung around a lakeside campground. Never bothered anyone, even when her cubs were present. She learned how to cause dumpsters to overturn using a rock and even taught her cubs to crawl into "bear-proof" dumpsters for her.
Some "undocumented migrant" shot her in self-defense (YEAH, RIGHT!). First words to the warden "Can I keep the skin?"