Anger is the emotional response to what we see as injustice or frustration. While society doesn't approve of injustice, it also doesn't approve of anger. As children we heard, Don't fight," or "It's not nice to get angry," or "Hold your temper!"
Anger energy is powerful, and ignoring it will not make it go away. Often it will smolder until it bursts into flames, or dam up until it seeps out like poison in ways that encourage illness. If repressing anger is your habitual response, you are likely to get into trouble. For example, a chronically tense jaw can misalign the dental bite, induce headaches, destroy teeth, and detract from a person's physical appearance. Unexpressed anger can feed resentment and lead to unpredictable explosions that upset your relationships and your mental balance. Many "nice guys" and "sweethearts" - those whose behavior in public is exemplary - are often hiding intense anger. Instead of sharing openly, they become covertly hostile, smiling as they stab you in the back. Because there are such strong cultural proscriptions against the expression of anger, this passively aggressive activity has become standard operating procedure in many societal institutions, including the workplace. If we were courageous enough to tell the truth - to respectfully and constructively communicate our anger - our world would very likely be a much more honest and peaceful place.