The truth about lies and deception…….honest.

I have read the terms and conditions. Surely the single greatest lie ever told, certainly in terms of the volume of us who have ticked that box knowing that really we haven’t.  However, deception breeds deception and with now defunct computer game shop Gamestation taking advantage of the aforementioned ‘fib’ by fiendishly incorporating into the smallprint of their online terms and conditions- that they owned the very soul of anyone whom blindly ticked the box -‘the immortal soul clause’ as it was called.  Over 7.500 people were caught out on April 1st 2010- they were refunded their soul in an email.


However lying, deception, untruthful, false, dishonest, mendacious, perfidious, duplicitous, dissimulating, dissembling and double Janus-facedness is a normal human behaviour, not just human, animals deceive too. Koko the Gorilla had been taught sign language and ruthlessly blamed the ripping out of a sink from a wall on her pet kitten (Koko signed on the return of her keepers…..”The cat did it!”).  If we are to take an evolutionary view it is a survival mechanism, a simple smile to someone you despise or you feel threatened by is a useful tactic to hide any weaknesses that may be exploited by them and hide, deceive them of your true feelings. However false smiles can be detected if you know where to look – the muscles that generate a warm and honest smile are different to those that are created  when creating a false smile. It’s all in the eyes…you see.

Those lying eyes

real-eyesThe eyes truly are the window to the soul. However don’t be fooled by so called Neuro Linguistic Programming techniques  (a good example of pseudoscience) that if someone is looking up when telling you something then they are lying there is little evidence to support this but is something that your hear still being pedled around every now and then.

And there lies the crux of the matter…are there any reliable physical cues to deceptiouniversal-facial-expressionsn?  Maybe a more fundamental question is are there any universal responses of facial expression or body language? (The eyebrow flash for recognition of someone  is thought to be pretty universal as an involuntary response.)   Certainly classic research by Ekman into facial expression has suggested that there are a handful of truly universal expressions. However deceivingly there is a long tradition of supposed cues to deception or ‘tells’ as gamblers would say little unconscious signs of anxiety, uncertainty due to knowingly attempting to convince someone of something you know not to be true. Going red, not being able to look someone in the eye, looking at someone for too long in the eye, rubbing the back of the neck, rubbing the ear lobes, scratching the nose, excessive blinking (note that psychopaths reportedly blink less and maybe that is why they are better at deceiving people) are all ways many think they can spot a liar – but where does the truth lie?

Bad Lie detectors

Many of these are signs of anxiety not necessarily deception, blinkinghowever Polygraphs (aka lie detectors)  have been used for many years in criminal investigations in the United States (and on the Jeremy Kyle show) and provided as evidence, however it measures variations in physiological arousal (not lying) and therefore fundamentally flawed, the American Psychological Association concluded:

The development of currently used “lie detection” technologies has been based on ideas about physiological functioning but has, for the most part, been independent of systematic psychological research. Early theorists believed that deception required effort and, thus, could be assessed by monitoring physiological changes. But such propositions have not been proven and basic research remains limited on the nature of deceptiveness. Efforts to develop actual tests have always outpaced theory-based basic research. Without a better theoretical understanding of the mechanisms by which deception functions, however, development of a lie detection technology seems highly problematic.

For now, although the idea of a lie detector may be comforting, the most practical advice is to remain skeptical about any conclusion wrung from a polygraph.                                          Cited;

F.B.I training focusses upon a range of techniques for detection .

Good lie detectors

Where humans on average can detect lies at marginally above chance level – 54% but surely professionals such as Police officers are better?  When Samantha Mann conducted research into a new area of lie detection and found some interesting results, there seemed to be a greater emphasis on story cues rather than the historic notion  body language cues of the more experienced and stronger lie detectors used in the research.  Detecting true lies; Police officers abilities to detect true lies.  Mann and Vrij’s research supports the view that often the focus on lie detection is in behavioural cues rather than the more accurate experienced police officers who also rely on story cues as a method of detection.

There have been a number of publications integrating a range of approaches to lie  detection.

Here is an overview of  an alternative piece of research conducted by Mann and Vrij investigating high stake liars.

Professor David Canter and colleague  may be  about to turn the whole area on its head with current research taking place at the Centre for Investigative Psychology on revisiting the use of polygraph techniques in the UK. 

The BBC recently compiled a practical overview of lie detection – View it here. 

The fun of deception

However, the detection of lies can be fun…………… a light entertainment kind of way.  The story cues on the clip below may seem so far fetched that it must be a lie…it must be………..mustn’t it?


You (probably) know nothing John Snow….

There is currently a battle raging………

Not the usual paradigm based Psychodynamic Vs  Cognitive argument this time something even more fundamental.  How do we analyse the data? Countless undergraduate Psychology students with a keen interest in the behavioural element of the discipline have long been found pouring over programs like SPSS  (or in my day Minitab) as they get to grips with the statistical element of research methodology – arguably the area many Psychology students would identify as their greatest weakness. When they do get round to even the most fundamental elements such as P values (the new A-Level specifications have returned to implementing a heightened level of knowledge regarding test choices and parametric vs non parametric testing) it is then the next stage of interpreting the conclusions drawn.  (Here is a great starter site for students to pick up the fundamentals).

Back to the battle……..A new (ish) contender has entered the ring.  Bayesian modelling is starting to become the statisticians choice of weapon over probability values calculating  rejection of the null.  All examples are best explained using…..Game of Thrones….of course.  See below an article from that uses Bayesian modelling to predict who is going to die next in Game of Thrones!


The Model

The idea is simple. Each chapter in the first five Song of Ice and Fire books is told from the point of view of a particular character, and Vale used the number of chapters dedicated to each character in each book to create a simple mathematical model to predict how many chapters might be dedicated to each character in the next two books. Of course, this method can’t predict specific storylines and plot twists. But it does allow for some educated guesses.

“Presumably, dead implies zero POV chapters,” Vale says. “So there should be a small amount of information about the potential deaths of characters if we believe the model.” For example, Vale’s predictions put the odds of Jon Snow having zero chapters in the sixth book at about 38 percent, and the odds of him having zero chapters in the seventh book a little over 67 percent. In other words, based solely on the model, it appears Snow may well be dead by the end of the sixth book.

But Vale doesn’t put much stock in his own predictions. “I am cautiously pessimistic about the model’s chances of giving a good prediction,” he says.

The Dearth of Data

That’s partially because there’s not much data available. Even at a whopping 5,216 pages, five books doesn’t give Vale much to go on. There’s also no real reason to believe there’s a predictable pattern to how many chapters a character will drive before being killed off. And, of course, the model doesn’t take the content of the previous books into account. That leads to some plainly wrong predictions.

The model says it’s possible that there will be chapters dedicated to characters already dead, for instance, and it says some characters, who are clearly alive, may not appear in any chapters. “In general, the best predictions are obtained by a combination of modelling and common sense,” Vale wrote in the paper. “Here we focus entirely on the modeling side and leave common sense behind.”

One of the big ideas of Bayesian statistics is that you can update your predictions as new data becomes available. So, once the sixth book is out, Vale could add that data to the model to make a set of updated predictions about the seventh book. But he doubts the model will actually do well enough for him to bother updating it with fresh data. Plus, he’s heard rumors that Martin will abandon the practice of writing each chapter from a different character’s point of view, which would break the entire model.

Ultimately, this is probably more of a lesson in what not to do when building a mathematical model. But while the paper might not help you win any betting pools, it does help get a sense of how mathematicians approach predictions—at least when they don’t have much else to go on.

Here is an excellent article that discusses in detail the extent to which bias in endemic within Psychology it also discusses  the Bayesian approach over p.  Including reference to Pennington and Hastie’s research into story order and mock juries in general.