Although everyone experiences anger in response to frustrating or abusive situations, most anger is generally short-lived. No one is born with a chronic anger problem. Rather, chronic anger and aggressive response styles are learned.
There are multiple ways that people learn an aggressive angry expression style. Some people learn to be angry in childhood by copying the behavior of angry people around them who influence others by being hostile and making threats. For instance, children growing up in a household where one parent constantly yells at and puts down the other learn to yell and put down others themselves, and then often recreate this behavior when they grow up and enter into relationships by yelling and putting down their partners. Someone who has learned to act in an angry way may not realize that they have an anger problem. From their perspective, they are just acting 'normally' (e.g., meaning normal for their family of origin).
A desire for revenge or mastery can also cause people to develop anger problems. An abused child may vow at some level to never again let him or herself be vulnerable, and start himself becoming hostile towards others on the theory that "a good offense is the best defense". Alternatively, abused or wounded people may overgeneralize and seek revenge against an entire group of people, only some of whom may have actually harmed them. As an illustration of this revenge principle, consider the sometimes aggressive prejudiced responses that some experience towards immigrants who come from countries that were once enemies of their country, or persons following to a belief system that is vastly different from their own.
Still another way people can learn to be aggressively hostile involves their being reinforced and rewarded for being a bully. People who bully someone once and then find others respecting or fearing them more for their aggressive actions become quite motivated to continue bullying. Bullies go on to use aggression more and more because they find that it helps raise their social status and position.