How Not To Spot a Liar

Again, more from the weird web department. This time, stumbling around the net brought me to a web page titled “How to spot a liar.” This is a page which explains how you can use eye movements, verbal constructions and blood flow to spot when people a lying. It is all packaged together well, and is generally an easy to read site.

The problem is, it is nonsense.

The bigger problem is that it is not pure, obvious nonsense, but the insidious nonsense which is latched on to some truth and then muddies the waters. Basically put the site discusses how eye movements can show which parts of the brain are being used, and how these parts of the brain have been (broadly) mapped onto construction or recall. That is about where it ends it’s relationship with reality.

For example, the site claims that when you ask some one a question, and they answer following a rapid eye movement up and to their right (your left), this means they are “constructing” the response and therefore lying. If they look up and left (your right) they are recalling the response and therefore telling the truth. As I said before, this is generally correct, but nearly half the population have this reversed. Makes using this a bit of a problem unless you know what you are looking for as you have an almost even chance of getting it wrong…

Add in to this the hazy use of recall and construct when it comes to answering a question and you can see that the most likely effect of taking this site seriously is to make you never know when some one is lying to you. Part of the art of getting a feel for deceit using clues like this, is learning how the question you ask influences the answer. Without that, even if you know which way the person looks, it wont help.

The examples given on the site are useful in this, and they highlight how the author of this post is turning slightly imperfect knowledge into a bad conclusion. This is the first example the author uses:

Let’s say that you have a friend who owes you some money. You have heard that they just got paid and you want to suggest that they pay you back. You try to be polite and ask them, “Did you get paid yet?” They answer, “Gee, not yet. The boss said maybe next week.” and look to their right (your left). This would indicate that they are constructing or “making up” what their boss said. They are telling a lie.

Whoa. The most important thing is the conclusion is false. It really is, even if you assume everything else the site says is correct.

First off, the question (grammar issues aside) is not one which would allow you to “spot” a lie using this method. It requires a Yes / No answer, so there is no real need for construction of a lie. Closed questions like this have their usage, but you need to get some on to talk for a bit longer to get a feel for what they are really saying.

More importantly, the construct does not mean they are lying about not getting paid. They could be constructing when they will get paid or they could even be constructing how they plan to react to your subsequent questions. Think about how you react to questions yourself. If some one asks you something, you will often find you answer, while anticipating how your answer will lead to other questions. This is a construct because it hasn’t happened yet. It is not a lie.

This leads to the critical item of importance. a construct is not a lie. If some one asks “Do you think this picture would look good on our walls?,” you have to mentally construct the image (and will have a visual construct eye movement) before you can answer. The site seems to hinge on the idea that a construct is a lie and that is probably it’s greatest downfall – especially as it is an interesting topic.

For those of a more devious bent, people who try to use this on you (without real knowledge) are easily defeated. When you want to hide some knowledge from the person, for example you are doing something you intend to deny later on, simply ask yourself a barrage of common questions and make sure you answer. In the future, when you are asked you will be able to recall your previous answer and give a “recall” response… (Note: This will not work on people who know what they are doing! Use at your own risk!)

Anyway, the site continues with a mix of good and bad stuff. From further down the page we get:

Another thing that forensic interrogators look for is the use of contractions — words like isn’t, doesn’t, weren’t, etc. These usually are used by people telling the truth. On the other hand, people who say is not, does not, were not, etc. are often lying.

Which is more nonsense. It is more dependant on the subjects culture and upbringing than anything else – not to mention that people who are telling the truth, but feel they are not being believed, have a tendency to formalise their language. Think back to a time when you were being asked questions and the person didn’t believe your answers, as you get more forceful with your defence there is the tendency to emphasise your words, so “I DID NOT …” gets used. Sadly, this is also true of barefaced liars, which is why it is a very, very bad technique to use.

One good point the site brings out (at last, one I agree with) is:

Another method used by professionals is to change the subject. A person who has been telling lies about a particular event will welcome the change of topic and will be visibly relaxed. An innocent suspect or a person who has been telling the truth will usually want to continue the dialog and will find the change of topic puzzling and attempt to regain focus on the topic.

This is one of the stronger signs, but again has to be used with caution. The innocent person may just think you finally believe them.

As always, a little knowledge can be a dangerous thing. Generally the site is interesting and worth looking over, but taking it too seriously, trying to use what it says (or work round what it says to get away with something bad) is a risky thing. Even with my limited knowledge, I can see flaws in what they have said, I am sure a professional could find much more.

Remember CSI is not real.

[tags]Society, Crime, Interrogation, Lie Detector, Evasion, Science, Psychology, Mind Reading, Body Language, CSI, Forensics, Crime Scene Investigator, Interview Techniques, Questioning[/tags]

3 thoughts on “How Not To Spot a Liar

  1. This is NLP isn’t it?

    I liked the first comment on the site you refer to, re George Bush’s eye movements when talking about weapons of mass destruction. 🙂

  2. Yeah, the bit about George Bush was funny – the problem is the eye movement signifies brain activity, so I suspect in his case it was simply just a random movement….


  3. 🙂

    I believe that may be another case where the standard answer to “how do you spot a liar” is “His mouth is moving”.

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