We all lie. And one of the first untruths we tell is about how much we lie. It's a self-protection thing - we don't want to be thought of as deceitful - and some of our daily deceptions are good lies and don't count, right?
Even when we believe we are being honest about how much we lie, we are still lying, because the human mind is startlingly good at deceiving itself. As the evolutionary biologist Robert Trivers writes in his book Deceit and Self-Deception: fooling yourself the better to fool others, humans developed self-deception as a way of better pulling the wool over other people's eyes - we won't look as if we are telling a whopper if we don't think we are. Hence, studies into the frequency of lying are problematic.
All this makes a teacher's job pretty difficult, given that they are tasked with hunting out liars on a daily basis. They have to see past the sheen of seemingly solid alibis and excuses and seek out the fake among the genuine. Late work, stealing, fights, arguments, plagiarism, sporting opportunism, flattery.the list of opportunities for fabrication is endless. And teachers have to deal with these falsehoods with little idea of the prevalence of lying, few methodologies for spotting it in action and the knowledge that many liars are extremely good at their craft.
So what can they do? Well, we have asked a primary teacher and a secondary teacher to reveal their best strategies. They say they work. But, then, I guess we have to face the reality, however remote, that they may be lying.
How to expose a liar in primary school
"I never poured strawberry yogurt into her coat pocket, OK?"
Kayleigh is still refusing to confess. At 8, she has already perfected The Look. It is a combination of shocked innocence and wounded pride. How dare I even suggest that she would commit such a crime?
The age of litigation has infiltrated the primary classroom and its key maxim - never admit guilt - has turned the sweet face of innocence into the deadpan of the habitual liar. And because primary teachers are forbidden from using medieval instruments of torture, lie detectors or scopolamine in their search for truth, there is only one resource left.
My do-it-yourself guide to dealing with primary school liars is based on painful experience and an extensive study of police dramas on television.
Psychology of the classroom liar
Classroom liars fall into three categories: the impulsive, the compulsive and the strategic.
Impulsive liars tell fibs at moments of panic. Theirs is an instinctive response to an unplanned moment of wrongdoing and they are easily identified by their red-faced guilt and wide-eyed desperation. Usually it takes only the slightest probing to elicit a tearful admission of guilt.
Compulsive liars, on the other hand, cannot help lying. Although they are often easy to detect, getting an admission out of them is impossible. I may cite 50 witnesses, reveal photographic evidence and provide indisputable forensic proof but their response will always be "it wasn't me". With compulsive liars it is best just to punish and be damned.
Strategic liars are the ones we need to target. Such children are generally intelligent, motivated and skilled in the art of appearing innocent. This makes them difficult to convict unless you can get help with your enquiries.
Getting help with enquiries
With teachers no longer permitted to beat confessions out of suspects, the investigation process should include one or more of the following procedures.
Launch a public appeal when there is no obvious suspect. Children will always respond to this. It is a fact that they enjoy witnessing the humiliation and ritual punishment of one of their friends and will do all they can to facilitate it.
Suspect and witness statements must be taken independently of each other in order to reveal areas of inconsistency and corroboration. Where it is not practical for an investigating teacher to be released from a lesson, this should be done in hushed tones just outside an open classroom door. The rest of the children are guaranteed to be quiet as they will be doing their best to overhear what is being said.
Technology is the ultimate weapon in a teacher's quest for truth and justice. It is the modern-day equivalent of the thumbscrew and pliers. In our school, it is well known that the infrared burglar alarm sensors are really cameras that relay images directly to the headteacher's office. "Best to confess, sonny. You don't want the guv'nor to waste her time trawling through all those videotapes, now, do you?"
Presume guilt when you are certain beyond reasonable doubt that you have the right culprit. For example, instead of saying, "Did you write `Gemma stinks' on this Post-it?" ask "Why did you write `Gemma stinks' on this Post-it?" This strategy works even better when you go on to imply that there might be an element of mitigation involved. For example, I might add: "But what did Gemma do to make you write this note about her?"
Once you have someone bang to rights, it is important that their punishment includes the three Rs: reparation, reflection and rehabilitation. A pocketful of strawberry yogurt is a particularly sticky situation to deal with but, in my experience, most crimes can be repaired with an apology, either spoken or in writing. A period of reflection, over the course of a playtime or in another class, should follow this.
But always remember that in a socially confined classroom the last thing you need is anger, resentment or injustice loitering around the margins, waiting to give someone a good kicking. To avoid this, ensure that the offender is rehabilitated into the classroom community with a cheery smile and words of encouragement.
Finally, always remain conscious of the fact that exposing a liar should be about making your classroom a happier and more humane place...hang on a minute, how did Kayleigh know it was strawberry yogurt?
Steve Eddison teaches at Arbourthorne Community Primary School in Sheffield
How to expose a liar in secondary school
Most lies are white lies, little benign bluffs used to protect someone's feelings or oil social interactions. But many lies aren't. For secondary students, untruths can be about gaining an advantage, seeking attention or avoiding sanctions.
So, how do you spot a liar? Well, you can forget about elongating noses or burning pants. Lie detectors don't work either. But there are behaviours that you can look out for. A liar is more likely to use phrases like "to be honest", "I swear to God" or "believe me" (or, if they are Richard Nixon, "in all candour"); to give less spontaneous responses and repeat tough questions in full; to show a mismatch between verbal and body language - for example, by saying "no" while nodding (it is usually the body language that is correct); or to touch their eyes or mouth or freeze their upper body.
Suspecting a lie, however, is not the same as knowing the truth. To find that out, it is best to take a strategic approach, which is precisely what John did when mobile phones were stolen from the girls' changing rooms during the second period. It fell to him as the pastoral leader of the phones' 13- and 14-year-old owners to investigate.
John took the READS approach. This stands for research, ease, ask, details and suggest.
John got as much background information as possible. He collected written statements from the girls and emailed all teachers to see if any student had been let out of lessons during the period in question.
Some of the girls identified Megan, another student in their year, as a suspect. They didn't have any direct evidence but there had been talk of her "stealing stuff". She was also on the list of students who were out of a lesson at the time of the theft.
John again emailed all staff asking if anyone had seen Megan (or any other girl) outside the changing rooms. No one had. He also had a chat with Megan's form tutor and her teacher from the second period. He then arranged to have a talk with the student herself.
John's aim was not to interrogate Megan, but to create a conversation that would encourage her to tell him all that she knew. If people feel threatened, they clam up; if they feel safe, they're much more likely to be open. Therefore, John was friendly, relaxed and warm. He built rapport by chatting about their shared interest in football. And he chose his words carefully, for example by avoiding "stolen" and using the less threatening "gone missing" instead.
Megan's story was that she "didn't even go near the changing rooms" but "went to the loo and came straight back". John knew that for him to be able to spot inconsistencies, he needed her to give a fuller account. Therefore, he asked lots of open-ended questions, resisted any urge to fill in missing information and focused on the when, where, who and what of the situation.
To bypass defensiveness, he turned "why" questions into "what" questions: "What made you go that way to the toilets?" and "What stopped you leaving your bag in the classroom?"
Once John got the outline of Megan's story, he focused on the details of her account.
Her responses became much less spontaneous. At one point she even repeated one of John's questions: "Did I see anyone outside of the toilets either when I went in or went out?" John saw this as a delaying tactic, with Megan trying to work out what would be the most deceptively useful answer to give. She plumped for "I don't think so".
In fact, John had been informed during the research stage that a group of students, overseen by a teaching assistant, had been working on a project right beside the girls' toilets. He didn't share this information with Megan but instead continued to ask her more questions about what she had and hadn't seen. Once he had a concrete answer, he told her about the teaching assistant and the students. However, he didn't turn it into a "gotcha" moment, but merely said that sometimes it was hard to tell the truth.
To help Megan come clean, John was empathetic and suggested a number of reasons why she might have taken the phones. One was: "Maybe you felt that those girls get everything they ever want and you wanted to even it out a bit." Showing empathy, whether or not it hits on the student's real motivation, tells them that you are trying to understand their behaviour.
In fact, all John's reasons were wrong. But one (or the weight of them all combined) prompted Megan to say that she didn't like the way the girls "strutted round like they owned the place". John asked if that was the reason why Megan "took" their phones. Megan hesitated.
John pushed just a little bit more. "You were trying to teach them a lesson?" he asked. "I suppose so," Megan replied.
So what happened to Megan? She was sanctioned, of course - that had to happen. But she also got pastoral and counselling support. If the truth hadn't come out, that support would not have come her way. But it did because John took a strategic approach that encouraged her to be truthful. It is hard to spot a liar, but the outcomes can be positive as well as punitive.
Robin Launder teaches in a pupil referral unit in Hertfordshire. He is also director of behaviour management programme behaviourbuddy.co.uk
Trivers, R (2014) Deceit and Self-Deception: fooling yourself the better to fool others (Penguin).
Serota, K B, Levine, T R and Boster, F J (2009), "The Prevalence of Lying in America: three studies of self-reported lies", Human Communication Research, 361: 2-25.
Wilson, D S, Near, D and Miller, R R (1996), "Machiavellianism: a synthesis of the evolutionary and psychological literatures", Psychological Bulletin, 1192: 285-99.
Work on deception by Bella DePaulo, visiting professor of psychology at the University of California, Santa Barbara.
Falsely accused by a pupil? Here's what to do next.
Dealing with a serial liar: "Don't get mad, get logging," says Tom Bennett.