This paper’s authors argue self-deception is an evolved trait with the evolutionary advantage of helping deceive others without severe cognitive strain. They suggest self-decpetion – which should in theory be paradoxical – is actually achieved through dissociations of mental processes, including conscious versus unconscious memories, conscious versus unconscious attitudes, and automatic versus controlled processes. The comprehensive paper goes on to contrast the author’s theories of self-deception with existing theories, and summarises the costs of self-deception.