nger may well be the most destructive of all emotional states--on the basis of good scientific evidence.  High levels of hostility predict development of heart disease, which makes sense when you consider the fact that high levels of anger cause your body to pump out a variety of toxic chemicals, such as cortisol, in preparation for a fight.
     Cultural factors come into play.  Western culture places a high value on anger.  We are supposed to feel moral outrage when someone steps on our rights, and in many conditions we feel justified in trying to avenge or destroy people who wound us.  You can see this in dragon stories around the world.  In Europe, the hero kills the dragon.  In Asia the hero makes friends with the dragon and uses its power. 

The general principle of war is that making the whole state surrender is better than destroying it; subjugating the entire enemy's army is better than crushing it; making a battalion, a company or a five-man squad surrender is better than destroying them.
     Therefore, winning one hundred victories in one hundred battles is not real excellence; winning a victory without fighting is the highest excellence.

Sun-Tzu, The Art of War