Anger Is an Emotional Response

Anger is an emotin that is observed across all cultures. Like most emotions, it evolved for survival purposes. When somebody cuts you off in traffic or says something contra your political beliefs, you feel a kind of indignation that your right has been grievously violated. It's not clear to me how expressing that anger is useful. If they o low somebody really thought i was a jerk, they're going to be like the traffic vigilante. So let's say this, i have anger toard them, but i haven't done anything about it.