The psychology of lying

The capacity to lie is noted early and nearly universally in human development. Social psychology and developmental psychology are concerned with the theory of mind, which people employ to simulate another's reaction to their story and determine if a lie will be believable.

The most commonly cited milestone, what is known as Machiavellian intelligence, is at the age of about four and a half years, when children begin to be able to lie convincingly. Before this, they seem simply unable to comprehend why others don't see the same view of events that they do — and seem to assume that there is only one point of view, which is their own.