Closer the relationship greater is one's intolerance. His own anger can overpower an angry person. This would blur one's vision making it more difficult to understand the main issues of a problem. Many relationships break because of this phenomenon. A conscious attempt should be made to develop one's patience, a quality that has to be with the best of kinsmen.
Anger also leads to revengefulness.
Family feuds due to revengefulness sometime are carried over many generations. If one looks back, the incident that caused revengeful action will be trivial. In fact, one could even laugh at it, if one reflects on that incident. However, there was no control of oneself at that time. One action has led to another and today the relationship is as bitter as ever.