The science of deception

Robert Trivers in The New Statesman:

My central claim is that self-deception evolves in the service of deception, sometimes by saving on cognitive load during the act of lying. It also provides an easy defence against accusations of deception (namely, I was unconscious of my actions). In the first case, the self-deceived subject fails to give off the cues that go with consciously mediated deception, thus escaping detection. In the second, the actual process of deception is rendered cognitively less expensive by keeping part of the truth in the unconscious. That is to say, the brain can act more efficiently when it is unaware of the ongoing contradiction.