Self-righteousness is the trust in your own righteousness and to believe that ones' self is better than others because of a system that a person was either born in or has established for him/her self.
We think of ourselves better than others because of whom we are, despite the fact that we are nothing but the sum of our experiences and the collective of our very limited knowledge.
For all of us, the building blocks of our consieous existence and what defines us is always the same, Religion, Color, Race, Education, Social Standing and status and even Nationality but what is it in all that, that makes some of us think we are better than others?