When we get angry , when we tend to lose sight of our long term goals and interests and act only in ways that are helpful to us in short term . For example we say things or do things in order to hurt the person we are angry at or to get angry at or to get revenge on them. These actions help us in the short term in that they make us feel good. But in the long term, they hurt our relationships with other people.
You make wish to research studies of the brain that explore the areas touched when people become angry, the neurological changes that take place, etc.
Anger prevents logical thinking. Usually decision made in haste, and don't hold up well to the light of day.