Lying, says the New Scientist, is a vital, smoothing part of the social fabric. We develop the skill young: most 3-year-olds will lie quite naturally when it suits them. The average UK adult admits to lying 10 times a week – even if these tend to be little white lies, like inventing reasons for not answering a phone call.

Robert Feldman of the University of Massachusetts Amherst and author of “Liar: The truth about lying” says that shifty eyes or showing anxiety – behaviours commonly associated with lying – aren’t consistent indicators. We are hopeless at detecting lies, for a good reason. “Most of the time we assume that people are telling us the truth. It’s really cognitively exhausting to always be assessing whether other people are telling the truth or not,” says Feldman.

The best liars are “natural performers”, says Aldert Vrij, a psychologist at the University of Portsmouth, UK. They “exhibit behaviours that observers associate with honesty, such as making eye contact, smiling and smooth speech lacking in ‘ums’ and ‘ers’, even when they are lying”, he says. Many successful liars also mask signs of thinking hard – and it seems good-looking people are more likely to be believed when telling fibs, along with lovable rogues (e.g Clinton). Human beings are also adept at serious deception, such as creating Ponzi schemes and leading double lives, and good at keeping secrets, compartmentalising our lives, and developing different personas at work and at home. ( adapted from part of a New Scientist series  of articles on human behaviour).

I think lying has to be looked at and judged by the motivation of the liar.  What  I would call fibbing  convincingly is an important skill that greases the wheels of friendship and social intercourse.  How many times have you, say, received a present that makes you groan?  Does the normal, civilised person blurt out his or her dismay? Are you really honest if you go to a dinner party where the food is awful and the host performs a two hour monologue?  No, to these and a thousand other social embarrassments or dilemmas, you feign delight and proffer thanks in  order not to offend.  This behaviour is so pervasive and normal as to be common sense. Life would be most unpleasant if we all told the unvarnished truth all the time.

Lying starts when you deliberately lie to someone over a major matter in order to avoid punishment, legal entanglements, and the desire not to offend becomes a desire not to end up in a police cell.  It is all a matter of context. You certainly cannot have a successful marriage or keep a job for very long if you are consciously deceiving the other person to protect yourself .  Epicurus, who believed in openness and getting on well with everyone around him, would have said that honesty is the basis of friendship, the ability to hold nothing back and  to do so with charm, a smile and an apology where necessary. You shouldn’t have to lie to a real friend, or to a member of your family.