NOTE: This is a cut & paste of my several of my posts on a different Thread, so it may not read well.
In my opinion the single biggest problem for Humans in Bears encounters, is their (Human's) natural reaction to retreat rather than stand their ground. This retreating by a human (even only one step) triggers the bears "Natural" Reaction to chase. And this is just natural behavior for humans and bears.
The young bears 2 1/2 to 3 1/2 years old are very lonely, very stupid, and very curious. Which makes them inclined to approach humans and human dwellings.
A very brief overview is, you have to watch young cubs reactions with their mother and even more closely the reactions learned between the cubs. She the mother will pick them (the cubs) up by the neck, and she will swat them. The little cub start to do this with each other as playful tag. The cub will take turns chasing each other, get caught and the one chasing will lightly grab the neck of the other.
This is sometimes played-out with three cubs, if there are three cubs still alive. It is chase-catch-subdue, the break contact. This is a key point Chase-Catch-Subdue-Break Contact. Note: this is note restricted to bears only....foxes & wolverines I have noticed doing this, including young bears playing Chase-Catch-Subdue-Break Contact with both foxes and also wolverines. I have never seen bears "Play" with young wolves. The sows do not seem to have any concern about her cubs playing Chase-Catch-Subdue-Break Contact with other species like fox or wolverines.
In my opinion this is what happens when a bear encounter's a human. If you watch the cubs as soon as they break contact, they fake each out back and forth to see which will run. I think this carries over for bears the rest of their life, Chase-Catch-Subdue-Break Contact. This is why "IF" a human is stupid enough to retreat they will get Chased-Caught-Subdued-(Now: if they fight being subdued, they will get mauled till subdued). If they surrender it is likely the bear will break contact. This explains why humans get mauled, the stops mauling and walks away..........but if the victim moves to soon, after the bear walks away, it will trigger another.....Subdue sequence, the bear will return and maul some more. If you look at this from the bears cub conditioning, you see it is more "playing" than attempting to kill the human. The problem is humans break very easy.
If you study the bear mauling of humans most are not fatal. But humans have soft shells and because the main way that cubs subdue each other is by grabbing the neck or ear of the other cub. Humans break easy.
The skittish and fearful behavior is about Size. The size of the human sillioute as compared to that of other bears. Bears are constantly judging the danger of other bears. This is the whole dance of hopping on their front feet, and popping their teeth.
The skittishness and fearful behavior is (in My opinion) caused by their fear of being killed by another bear. I don't think it is a fear of humans as much as a fear and skittishness of any animal that stands and watches them. I think their filter is first can I (The bear) make this other "thing" (human or bear or caribou) run or retreat. As soon as it see's that the other "thing" is not retreating or worse running towards it, it shifts to skittishness and fearful. This is why you ofter first notice a close bear just standing there watching you.
On a slightly different bear behavior subject........I have been "Stalked" (5) five times by bears and this stalking is a completely different type of bear behavior that any other bear behavior. And very comical (unless you are not watching and it startles you and you jump......triggering Chase-Catch-Subdue). They stalk by circling and hiding, well hiding their head, leaving their huge Butt up in the air. This is a serious behavior, and it is hard to snap them out of this once the stalk has started.
There is a big difference between a direct (More or Less) straight line approach and this stalking behavior. I have never been stalked by a black bear, they were all grizzly/ brown bears. Three of those times it was with a client and we were not after bears. The other two times I was alone.