In the beginning, and for most of the story, Ulrich and Georg are both stubborn and vindictive. They have inherited a quarrel that is not really theirs. Yes, technically Ulrich owns the land and Georg is therefore trespassing. But to take this argument over an insignificant piece of land to the point of wishing death upon one's opponent is quite ridiculous. It shows how Ulrich and Georg both have reactionary attitudes. In other words, both men are set in their ways and refuse to reconsider things. This is especially evident in how they accept, embrace, and perpetuate the feud they have inherited.
Their attitudes do change, however. When they find themselves with something in common, the opportunity for change presents itself. While both men are fighting for their lives, trapped under the tree, they are initially stuck in their reactionary ways. But after an initial gesture by Ulrich and momentary resistance from Georg, a friendship begins. They end their allegiance to the feud and they become united in trying to survive. The shift is complete, going from narrow-minded to open-minded, from blindly following tradition to embracing the new.