I had an ol'dobie who was absolutely great...and one thing about a lot of dobes...is their ability to 'detect'. Analogy: my dobe would whine a leetle bit and nuzzle me if he heard a car door or simular little sound at the end of the driveway...but a sheperd might be more inclined to just sit and 'wait for it'.
On the other hand, a sheperd is more likely to fight to the death than a dobe who might just decide that if things are too firece - just to back off... (a gross generalization)
I had one dobe that was the smartest and most loyal dog one could imagine(a beta - a big boned red dobe) and I had a little blue alpha female who couldn't retrieve at all and who would take off running away...at times when I least expected it. I note some people like hybrid wolves...and they might be dandy if mixed just right...but one thing to remember...is a wolf is 'less aggressive' than a dog, but a dog is 'less predatory' than a wolf. Dogs barks and bs around, but a wolf is more laid back and cool about things... So if you mix'em up a little bit the wrong way - you can end up with hybrid that's both aggressive and predatory - and I'll just say 'not for me.'
What's interesting is 'environment' and 'adaptation'. I've scuba dived in the keys where it was like an aquarium...but in Belize I'd see the same species and they seemed more 'aggressive'. I imagine bears are the same ie. they adapt to different environments... In Russia, there's lots of stray dogs and it's funny ie. they all seem to have the same size and 'look' - but I don't see any laying dead in the street hit by cars... One day I was walking down a street in Kishinev Moldova and came to a crosswalk and dang it if the stray dog in front of me didn't stop and look both ways before crossing the street!
Adaptability ! The dogs there also tend to be very sneaky and quiet in regard to getting food from trash cans...
In fact, it's neat when you think about it - but ask 'How long have these dogs been around' and the answer is mind blowing. These stray city dogs - or village dogs - that are all around the globe in Europe, Asia and Africa - have maybe been there longer than the people ! They're generally all about the same size like hairy little wolfish little coyotes that have adapted to human cities and villages. Bears are highly adaptive too - but not nearly so successful or capable as dogs.
I imagine bears can vary in aggression from area to area - and turn it on and off under various environmental circumstances. The seduction is that sometimes a Grizzly Bear can look so friendly and innocent that one could almost reach out and pet it... but in a sense it is always an illusion.
Interestingly the now extinct short-faced bear was twice as big as a Grizzly and had a leaner build. He was very fast and had a bulldog-like face. He could slam into a mammoth or simular megafauna and take it on ! He was also almost entirely carniverous - unlike Grizzlies/Browns who are more omniverous - and that one factor probably caused his extinction. He couldn't adapt... When modern bears are under stress - a bad berry season or a poor salmon run - it puts enormous pressure on them to adapt. Part of that adaptation might be becoming 'more carniverous or predatory' or in the reverse scenario 'less carniverous or predatory'.