I always understood the bear attack issue to be as follows:
Mother with cubs, regardless of bear species, she attacks to protect the cubs. She feels your a direct threat to the cubs. Mothers with cubs will often attack much larger bore's if they get to close even if the bore shows no interest in the her or the cubs. I beleive this to be the majority reason a mother with cubs attacks a human. I'm sure if she and her cubs are starving, she will attack to eat a human. Most people, who have been attacked by mother/cubs, live to tell about it. This means to me, she did not want you for food. Because if she did, you would not live to tell about it. If she wants to make you lunch, you are dead meat.
Black bear attack (mother without cubs) in general are preditary. The bear wants to eat you. The bear is very hungry and not enough food source int he area.Playing dead wil not work. Im fact, palying dead will get you eaten. Fight like hell and perhaps they will try something less willing to fight.
Griz attacks. They are mostly territorial. They attack because they sence your eating there food source. Because these bear are usually very large and visious, you are usually killed by the attacking bear, not nesesarilly eaten.
