presumed, What works with people doesn't work with bears. they have poor eyesight( relatively speaking), but superb audio and olfactory systems. Standing up is not so much an aggressive posture, but merely trying to get a better look. Interesting reference though! Another strategy, is to simply pitch your camp truly out of the way. In regulated parks, I deliberately, and illegally camp away from designated campsites. The bears ( and thieves) know every square foot of their territory. Campgrounds with igloo care baskets are part of that knowledge. This does put the burden of utterly zero impact camping on me ethically.