From “Seven Deadly Sins: The Biology of Being Human” by Guy Leschziner
When uncontrolled and unfiltered, anger can be destructive either through the intensity of the emotion, as in rage, or in its physical manifestation of violence. Anger has some very clear positive aspects, however. If individuals are given a puzzle to solve (one that is actually unsolvable), some respond with despair or dejection, while others respond with anger. When given a second puzzle, this time one that does actually have a solution, those who experienced anger with the first perform much better, and persist in their efforts for longer. Anger is the emotional response to being thwarted, being treated unfairly or not receiving an expected reward, when situations or the actions of others block our ability to achieve a goal. Anger is a motivator, a drive to continue striving to reach one’s objective.
But as a driver of behavior to achieve, to attain, to possess, it can sometimes lead to aggression. Most people experience anger very regularly without recourse to violence, though not all. While anger is the emotion, aggression is the behavior – intended to harm, to inflict damage on someone else. And while anger does not automatically lead to violence, high levels of anger as a personality trait predict aggression, and domestic violence, poorer functioning in the wider world and interpersonal problems.