Self-righteousness (also called sanctimony, sententiousness, and holier-than-thou attitudes)"Holier than thou" originates from the King James Bible, Isaiah 65:5, in which such an attitude is condemned is an attitude and belief of moral superiority derived from a person deeming their own beliefs, actions, or affiliations to be of greater virtue than those of the average person. Self-righteous individuals are intolerant of the opinions and behaviors of others that they deem to be less moral and virtuous. A self-righteous person will often exhort or rebuke certain behaviors and actions from others.
See also
Elitism Mississippi Squirrel Revival Narcissism Sanctimommy Signalling theory Superiority complex The Mote and the Beam The Pharisee and the Publican Virtue signalling
References
Further reading Good Mrs. Hypocrite: A Study in Self-Righteousness