Moral hypocrisy

Moral philosophers often assume a causal link from moral reasoning to moral action, but there is limited evidence for this link. People’s ability to see the morally right path does not guarantee that they will follow it.

Evolutionary biologist Robert Trivers suggested that if one can convince oneself that serving one’s own interests does not violate one’s principles, one can honestly appear moral and so avoid detection without paying the price of actually upholding the relevant moral principle.

http://psychology.iresearchnet.com/social-psychology/antisocial-behavior/moral-hypocrisy/