In my past life as a psychologist, I came to the conclusion that anger is the brain's response to violated expectations. Our evolutionary wiring has been shaped by the fact that our survival depends on predicting events correctly. (See my article, "The Sweetest Words in Any Language.") So the unexpected sets off alarms in our limbic system. That biological feature doesn't serve us so well anymore, as it is now manifested mainly in an obsessive need to be right. Philosophy can help, as can religion if it keeps us humble in healthy ways.