Few have been so angry that they see red. The redness seen (as a cast over the visual field) is the result of increased blood flow in the eyes caused by a huge outpouring of adrenal hormones.
This level of anger is violent. Temporary insanity is sometimes not an effective defense because so few jurors have had that kind of experience.
In cultures around the world, the verbal language of anger and the body language of anger are used as warnings. Often, people pretend to be angry when they are not really upset at all. They are just taking care of business.
Still, we have a large number of impulsive murders. Some kill unruly children without planning to do so.
Eventually, if you practice getting angry, you will get good at it. This is true also of resentment, envy, hatred, and all of the other destructive feelings learned during the many barbarian centuries and perpetuated by imitation in most cultures since. The world would be very different if each of us considered such feelings inappropriate in all circumstances. We were not born with these feelings.
Purging these destructive feelings is not any kind of suppression or amnesia. They may be part of your history, but they will not automatically recur.
This method works for every person who actually tries it:
The first step is to fervently wish for these changes. When a person can change such feelings, then habits, aversions, inclinations, and many other features can be changed.
A few times a day, imagine yourself with people in circumstances that usually prompt some feeling or action that you want to eliminate. See yourself acting differently and not reacting as usual. See yourself behaving as you wish you would. See yourself not feeling what you usually feel in those circumstances, but feeling empathy or love or understanding or courage as you would wish to feel in those circumstances.
If this sort of daydream in done a few times a day, you will see changes (verified by others) within a few months. That is my experience and the experience of a great many others.
A member of the Goodness Investigators, decades before his tranquillity training, had a history of anger which began in early childhood. His father, after many signs of rejecting the child, drove him to delusions and hallucinations at the age of five by telling a group of children and their parents on a sunny Saturday morning that he (the child) was one of many offspring of Adolf Hitler. He also said that an American General ordered him to marry the child's mother. This fiction lasted util age eleven when it was known that Hitler had no children. His dreams were routinely of murdering his father.
He didn't know this until his early 40s, but his father was driven to similar childhood problems by the time he was seven years old.
A contrasting story was told by a person not associated with the Goodness Investigators that continues his severe and predominant anger to this day (seven decades later). As a young child, he was told by his mother that his brother (of about the same very young age) was the real brains of the family.
Sometimes the course of a person's life depends upon a mere scrap of information.