I am fascinated by this video. It's funny but at the same time interesting what is going on. They are both wrestling in a friendly way. The kid obviously doesn't know anything but uses his natural leverage to try to take the bear down, which he does a few times. Natural leverage meaning his height advantage which gives him added leverage to lever the bear over. The bear relies completely on instincts. Even though it is an animal that doesn't have hands like humans, or can stand forever on all hind legs, it naturally knows how to redirect its weight. Constant shifting its weight, using foot work, it never even lets his legs cross over like humans would. Constantly circling, cutting the corner, using its head to steer.
It naturally clings as I've discussed previously, always pushing the kid at angles, trying to get behind the child at every moment. When the kid does take the bear down, the bear immediately uses its hips, and angles himself either on top or pushes the kid away with its limbs and gets back to his feet. It also hip escapes backwards out and gets back on top. It also always turns toward the child, never turning his back. Whereas the child turned his back several times.
Almost all animals will stand on hind legs to fight. We start on our hind legs. It's almost impossible to hold or pin the bear because of its natural awareness of space and distance. Try holding a dog down as compared to a child.
This is why you would never really want to fight an animal. We need to be taught these lessons of physics, whereas animals know it instinctively.
The child for his part naturally understands leverage and knows how to use his weight to drag the bear down, and also knows to keep trying to get back to his feet. How many adults would know that much?
It's why children are such wonderful students.