So just a thought, but what if there were a "feeling of victory" buff that erased the negative buffs like fear from fighting bears after defeating them? There could be some positive influences from it as well, maybe a learning gain temporarily. Also, you could make it only hit when the character fights something equivalent to their humor levels. For instance, at 5 humor a rabbit would give it and anything above, 20 humor beaver/deer 40 humor and above bears. Just a suggestion.
Brad