The truth about lying - the science of dishonesty

The new manager of the gift shop at the John F Kennedy Center for Performing Arts in Washington DC had a problem. The shop, which was staffed by elderly, mainly female, volunteers, who gave up a few hours each week for their love of art, was a hit, selling around $400,000 of trinkets and postcards a year. But annually, around $150,000, or 40% of that total, disappeared, compared to the average loss in a department store of three%.

Who was responsible? One staff member, who took cash to the bank, was caught with a pilfered $60 in his pocket and was promptly sacked. But the losses continued.

So the manager decided to make a change. Up until this point, the shop had eschewed cash tills; trusting the volunteers with simple boxes, into which they placed the takings. As soon as volunteers were asked to record each transaction the losses stopped.

There was no dastardly Raffles at work, it transpired. Instead, scores of cultured old ladies were snaffling small amounts of cash and goods worth just a few dollars a piece, as opportunities arose.

"It's not an uplifting story, but it tells us a lot about honesty," says Dan Ariely, professor of psychology and behavioural economics at Duke University, North Carolina, and author of The (Honest) Truth About Dishonesty, How We Lie To Everyone - Especially Ourselves.

"It shows that only a tiny minority feel comfortable stealing a huge amount, but that given the chance, nearly everyone steals and cheats a little." Ariely is one of science's supreme communicators, full of anecdotes to explain his theories, but his published work is based on 10 years of experiments carried out by him and his colleagues at Duke. His theory about small-scale cheating, for example, is backed-up by a maths test which was sat by thousands of people. The scientists weren't interested in the participants' numeracy, but rather the way they marked their papers. When the participants were told to give them to someone else to mark, they received an average of four correct answers (out of 20), but when they were allowed to mark their papers themselves, they claimed to have an average of six right. In other words, virtually everyone cheated, but only by a small margin.

"We're driven by two opposing motivations," the charming, chatty Ariely says down the phone from his native Israel. "There's the financial motivation to make as much money as possible, which drives us to dishonesty. But there's also the ego motivation, which makes us need to look in the mirror and see a decent person." Morality, it seems, is like a diet. We allow ourselves the odd Hobnob lapse, so long as we eat salad most of the time. In another of Ariely's experiments, two researchers, one obviously blind, were sent to a taxi rank in Tel Aviv. The sighted man tended to be driven the longer, more expensive route, while the blind man went straight to the destination and often had his fare rounded down.

"You can cheat most passengers, but that's OK because you're kind to blind people," Ariely explains.

And Ariely's work has shown that such moral self-justification can take many different forms. When customers in a cafe were asked to take a test, a waiter handed out money to each one, saying it was their $5 fee for taking part. But, in actual fact, he gave them each $9. When the waiter was polite, 45% of participants returned the change. But when he stopped in the middle of a conversation with them to take a call on his mobile, only 14% offered change. "Because they'd been irritated, they considered some dishonesty permissible," says Ariely.

Here my conscience slaps me, reminding me how - as a student - I justified fare dodging on buses by the fact the service was dreadful anyway.

Alarmingly, such self-delusion is rife - and on a far greater scale. The banks lied to us about Libor. Politicians fiddled their expenses. Athletes use performance-enhancing drugs. Every week the Leveson inquiry highlighted more examples of the media, in the words of the late MP Alan Clark, being economical with the actualite.

Ariely believes that corporate dishonesty works on the "everybody's doing it" principle. In what he calls his "Madoff" experiment, after the notorious financial con man, he asked a student blatantly to cheat in a test and be seen to get away with it. Students who observed such subversive behaviour were more than twice as likely to cheat themselves. When the cheat wore a sweatshirt of a rival university, however, students still cheated - but in smaller numbers, because they considered him an outsider, and therefore suspicious.

"Similarly, if one banker's known to be fudging the numbers and getting away with it, the other bankers are likely to do the same," he says. "They can justify the fudging because someone in the group is doing it, and, anyway, it's for the good because it's about maximising shareholder value."

If this is depressing, we need to remember that mendacity exists across the species. Orchids mimic female insects in order to attract male insects who will pollinate them. When threatened, the hognose snake likes to fake its own death, emitting foul smells and letting its tongue hang out of its mouth accompanied by drops of blood. Observations of apes demonstrate they're prone to all sorts of fibs. When they're in trouble for bad behaviour, baby chimps distract their elders by pretending an enemy is approaching.

The human capacity for deceit is far more sophisticated - which is why we're at the top of the evolutionary tree, according to Ian Leslie, author of Born Liars, Why We Can't Live Without Deceit.

"Lying is a sign of how creative we are as a species," he says. "We don't have the physical power and speed of other animals, but we do have the ability to see things in terms of possibility and potential. We can make things up and hope they will become true later."

To show how positive lying can be, we just need to look at the history of psychology and psychiatry. This used to categorise the insane as those who'd lost touch with reality. But now, the far more widely accepted view is that a healthy human mind actively dodges the truth. As T?S Eliot put it, "Human kind cannot bear very much reality."

"Most of the time, we all go around with a slightly inflated perception of our own abilities - that we're better looking, more effective, ethical and likeable than our peers," says Leslie. "We're over-optimistic about the future and we look back on our past through rose-tinted lenses."

Those whom Philip Larkin called "the less deceived", who judge themselves objectively, are more likely to be moderately depressed (as opposed to severe depression, where people harbour overly negative illusions about themselves). Tests on swimmers where they were shown two words simultaneously - one positive, one negative - showed that the competitors who shouted out the positive ones and ignored the negatives were more likely to win races.

"It makes sense that selection would favour people who are over-optimistic, who will try to climb a hill instead of thinking it's too steep. We're selected for that slight bias," Leslie says.

Sanity apart, most of us agree that society couldn't function without liberal use of white lies. Psychological tests repeatedly show that we tell an average of three fibs a day, and deceive 30 people a week. "We know lying is wrong, but it's more wrong to hurt people's feelings," Ariely says.

When Ariely, 43, was a teenage military trainee, chemicals he was mixing exploded, leaving third-degree burns on 70% of his body. In hospital, the nurses assured him a forthcoming operation wouldn't be painful.

"It turned out it was agony, but in the six weeks before it came up, I wasn't scared. I was incredibly grateful for that lie." Even the Bible doesn't explicitly censor lying, instead stating ambivalently: "Thou shalt not bear false witness." Theological scholars have been wrangling for centuries over the incident in Genesis 22 where God tells Sarah she's pregnant. She exclaims: "With my husband [Abraham] so old." Speaking to Abraham, however, God relates her reaction as: "I am too old."

But not everyone agrees with God. American psychotherapist Brad Blanton is the founder of the Radical Honesty movement, which espouses that everyone would be happier if we told the truth all the time.

Blanton's objections to lying aren't moral - he says he does lie on his tax return, an admirably honest admission in itself, and would lie to a Nazi officer at the door if Anne Frank was in the house. What he has no time for are the blandishments of everyday life. "Withholding and lying is the primary source of modern human stress, the primary cause of most anxiety and of most depression," he says.

He says it's better to tell your wife she looks ugly in her dress, so she can choose a prettier one, and to tell your boss you hate him instead of letting resentment fester. "We can all get over having our feelings hurt and being offended. These are not permanent conditions," he says. The benefit is greater intimacy. "That's not possible if you're hiding something for the sake of someone's feelings." But what if you're removed, physically, from the person with whom you're interacting? Ariely believes our growing reliance on electronic forms of communication heralds an increasingly dishonest future.

"The more communicating we do online, instead of face-to-face, the more our crimes seem victimless, and all our research shows that these are the crimes we are happiest to commit, because we have no sense of hurting anyone," he says.

The illegal downloading of music, films and books has reached a point where virtually no one under 25 regards it as a crime any more. The Russian edition of Ariely's book was downloaded illegally 20,000 times on its first day in print. "Perhaps if I described how many hours and nights I worked on it then readers might appreciate my effort and feel worse about their actions."

Downloading aside, what else can we do to make our society more honest? Ariely thinks we need constant reminders of honour codes. When he asked one group of students to recall the Ten Commandments and another to recall their 10 favourite books just before a test that offered opportunities to cheat, the latter group cheated moderately, as usual. None cheated in the former group.

In another test, participants filled in a paper resembling a standard US tax form. Students who signed disclaimers at the end, as is the international norm for official declarations, cheated as usual. On the other hand, students who signed before starting the test still cheated - but far less.

"If people are regularly reminded of moral codes, they're far less likely to misbehave," says Ariely. "People want to be good. You just have to remind them that's what they want." So next time you employ a classical-music-loving old lady to man a cash desk, hand her a Bible and ask her to swear on it. If not, you'll have only yourself to blame when stock checks don't tally and receipts don't add up.

The (Honest) Truth About Dishonesty, by Dan Ariely (HarperCollins, pounds 16.99)