'Born Liars', by Ian Leslie claims that all people are born liars and that around the age of four, children start to become more accomplished in the art of lying!
Dr Victoria Talwar, assistant professor of child psychology at McGill University in Montreal, had used the Peeking Game, a known experiment, to show the difference age makes to lying.
Young children, below the age of four usually lie to avoid punishment. But between the ages of three-and-a-half and four-and-a-half, they learn to lie with sophistication and skill. They are getting successful at understanding what the truth is, and yet think of an alternative story that would make sense and be believed by a hearer. They are becoming good jugglers - with the truth and their lies!
It is only when a child continues to lie persistently, even at an older age, it should cause concern, as it signals a deep-rooted problem that may persist into adulthood.