Why bears tolerate us?
If you are looking to go on a bear photography trip I suspect you may be asking, why are people this safe with an animal that has such a nasty reputation. There are a few things I must point out here. First, the bears we are visiting are the coastal brown bears, not the interior brown bears often referred to as grizzlies. There are some key differences. Also, you're safe if you listen to the people who take you there; if you are out on your own without knowledge of brown bear behavior you are taking a greater risk. One biologist put it this way "Habituated Coastal Brown Bears are not less aggressive than other browns, they are just less shy". Why the bears let you and others so close has intrigued many for years and has been studied intensively.
The bear’s tolerance of you really has nothing to do with their reaction to people, but how they have changed their behaviors because they are is such close proximity to other bears. The high density of bears is why coastal bears are different from interior brown bears or grizzlies, not a gentler nature. Most bear experts agree that all brown bears have a personal space they require; if any bear or person violates that space then they either flee or fight. This "space" requirement has been called several things, the bear bubble, the magic circle of the bear, or the more technical Overt Reaction Distance (ORD) which is the technical term used by biologists.
The theory is that brown bears usually have a large personal space, and anything violating that space will be attacked or it will flee, depending on how they see the situation. However, in areas of high density such as a coastal grass field or especially salmon fishing areas, the bears either will spend all their time fighting or fleeing, or they have to reduce that distance. So in general, coastal bears do not have near as large a distance they need for "space" as bears in Yellowstone or Denali out of self-preservation (reducing fighting with other bears and sharing rich food areas), not a gentler less aggressive nature. Scientists have studied brown bear attacks on people, and the interior bears, where the bear density is much lower tend to attack from people much further from them than coastal populations. So actually, you are safer in a high density bear country than low, because the bear bubble or ORD is not as large.
Most of the bears in the areas we will go have been habituated to people, and it took these guides/rangers time to develop the habituation. Bears we see now have grown up with people, as the bear viewing industry was well under way by the time most bears seen were born. However, they are not zoo animals either and that seemingly gentle sow suspects her cub is in danger she will get aggressive. They are not monsters, nor are they teddy bears and they need to be treated with respect. They are the largest and most athletic land carnivore in the world, but if you listen to your guides you can very safely photograph them as they live their life the way coastal brown bears have for at least the last 15,000 years.