For the death metal band, see Hypocrisy (band).
Hypocrisy is the act of condemning or calling for the condemnation of another person when the critic is guilty of the act for which he demands that the accused be condemned. Though hypocrisy is frequently invoked as an accusation in debates, a few theorists have studied the utility of hypocrisy, and in some cases have suggested that the conflicts manifested as hypocrisy are a necessary or even beneficial part of human behavior and society.

Etymology
Merriam-Webster defines hypocrisy as "a feigning to be what one is not or to believe what one does not."
Webster's New World Dictionary defines it thus: "A pretending to be what one is not, or to feel what one does not feel, especially a pretense of virtue, piety, etc." It defines hypocrite as follows: "a person who pretends to be what he is not, one who pretends to be better than he really is."
Since the root of the word comes from actors acting a part, the definition as laid out in dictionaries makes sense. It appears popular usage uses the word to mean something different from its dictionary definition.
Popularily, it is believed an act of hypocrisy has the aim to condemn another person or people, but not to condemn an act; when the critic makes verbal attacks or demands of punishment against perpetrators of the act that one practices oneself. The word hypocrisy is used to mean, simply put, the pot calling the kettle black. One is hard put to find dictionary support of that meaning.
Hypocrisy, then, consists of pretense, feigning, phoniness, being two-faced, insincerity. The theme of insincerity underlies the words of Jesus in the Christian Bible when he calls certain Pharisees to task for being hypocrites, i.e., insincere in their religious practices.

Defining hypocrisy
Hypocrisy has been described alongside lack of sincerity, as a characteristic which attracts particular opprobrium in the modern age.

Psychology of hypocrisy
Hypocrisy is often utilized intentionally as a form of sarcastic humor, not only in film and television, but among the population. Of course, there is a distinct boundary between humorous hypocrisy and what can be interpreted as serious hypocrisy. Often, if the hypocrisy act is carried out too long, one may get the impression that they are serious. Another form of serious hypocrisy that was intended to be funny is when the listener does not realize that it is humor, or when the speaker insults the listener. In comedy writing, this is sometimes called a "Stan Daniels turn," a joke setup where "a character says something and then does an immediate 180-degree shift on what he just said," according to The Simpsons producer Al Jean.

Theoretical issues

Tu quoque
Moral absolutism
Moral relativism
Pot calling the kettle black
Champagne socialist
Discourse on Judgementalism