Lie detector and behavioral signs of deception

Detector operators never make their conclusions about the subject's lies, based solely on the readings of the instrument. They know not only the results of the preliminary investigation, but also the information that they themselves received - an interview with the suspect before passing the test (during a story about the procedure and possible questions). In addition, the operators read the information of facial expressions, voices, gestures and ways of speaking both during the preliminary interview, during the test itself, and in the interview after it is completed. Opinions were divided as to whether the detector operator should consider the behavioral signs in addition to the test results, in addition to the test results. The materials I reviewed about those who take note of the behavioral signs of deception, unfortunately, are regrettably insignificant and are not based on any recent published findings. Most of the ideas contained in these papers regarding the interpretation of behavioral traits are simply incorrect.
So far, only four studies compare results based on detector readings and behavioral signs with those obtained on the basis of instrument readings only. Two of them suggest that the accuracy of behavioral signs is equal to the accuracy of detector readings, and one - that the accuracy of the detector is higher, although not by much. And all three studies suffer from those flaws: the uncertainty of truth, too few suspects and too few operators to decide ^[172] .
These flaws are corrected in the fourth study, in the study of Raskin and Kircher, which has not yet been published ^[173] .
They concluded that judgments made on the basis of behavioral signs are no better than random ones, while judgments made on the basis of detector readings without contact with the suspect still have a better result than random guesswork.
People very often miss the behavioral signs of deception, misinterpret them, or are simply mistaken about them. Recall my report at the beginning of Chapter 3 “Detecting deception by words, voice and plastic” about our research, when people could not tell from the video recording whether students who describe their emotions lie or not. And yet we know that such signs, although unidentified, existed. When the girls lied, hiding the negative emotions they experienced when watching a film about surgery, the tone of their voice became higher, they showed certain gestures, illustrating their speech, and made emblematic reservations (shrug). We have just completed a detailed description of mimic attributes, but still can not publish the results, despite the fact that they promise to be the most interesting in relation to the identification of lies. And the most expressive mimic sign is the one that gives out almost elusive movements of facial muscles, expressing disgust or contempt in quite happy looking smiles.
And we would like to determine what exactly is happening: people really just don’t know what to look at, or it’s impossible to see. Next year we will do just that; we will collect a group of people, let's say to them what we should pay attention to, and then we will show the videos. If their judgments are wrong, we learn that the accuracy in detecting these behavioral signs of deception still requires slower and repeated viewing, as well as more accurate means of assessment.
As for the research of Reskin and Kircher, it would be very interesting to compare the accuracy of judgments based on the detector’s readings with regard to behavioral signs with the judgments of trained, experienced, not naive observers. I believe that to some extent such combined judgments would increase the accuracy of detecting lies. After all, behavioral signs can give information about what kind of emotion is being tested, and perhaps the detector is able to determine fear, anger, surprise, fatigue or arousal?
Of course, such specific information can also be extracted from the detector readings. Let me remind you of our conclusions (described at the end of Chapter 3 "Detection of deception by words, voice and plastic") that different emotions of the ANS correspond to each emotion. However, no one has yet tried to apply this approach in interpreting the detector readings. Information about specific emotions (obtained simultaneously from behavioral signs and indications of equipment) could help reduce both errors of unbelief of truth and errors of faith of lies. Another important issue to be considered today is how well a combination of the detected behavioral signs and detector readings are taken by the suspect countermeasures.
The detector can only be used in relation to the willing to cooperate, willing suspect, and behavioral signs are read and without any permission and warning that the liar is under suspicion. In addition, while the use of the detector can be declared illegal, it is impossible to do the same with observing behavioral signs. And even if the detector tests never recognize as a legitimate means of identifying civil servants who are leaking secret information, verifiers can still study the behavioral signs of all suspects.
In many areas where deception is often suspected, such as diplomacy, marital relations or trade, the use of a lie detector is simply impossible. And the point here is not that since in these relations truth is not supposed, there is no possibility to arrange a strict and consistent interrogation, as during the investigation. Even where truth is presumed, such as in relations between spouses, friends, parents and children, such direct questions in general can jeopardize further relations. So even a parent who has more power over his child than any verifier over a suspect is unlikely to pay such a price for his investigation. Reluctance to recognize that the child for the most part still tries to tell the truth, the constant suspicion of him, even when the child is completely dependent on the parents, may eventually lead to a complete break with him.
Some people believe that it is better (or more moral) and not to try to reveal a lie at all, but to always believe in the word and, perceiving life as a value in itself, do not even strive to reduce the possibility of being deceived. It is better to be deceived than to unjustly condemn anyone. Sometimes it is really the most correct move. But it largely depends on the fact that the card is made, who is under suspicion, what is the probability of being deceived and who is the verifier himself. It would be interesting, for example, to compare what Jerry would have lost from Updike's Let's Get Married novel by believing in the truthfulness of his wife Ruth if she was lying, with what he would have lost or gained if she was honest. In some families, the damage done by a false accusation can become much harder than damage in the event of a real deception. It all depends on the specific situation. Some have no choice at all; and some are too fearful to risk believing lies; they would rather wrongly accuse anyone of deception than be deceived.
The only consideration that you should always keep in mind when trying to choose one or another solution is the following: never make a final conclusion about whether the suspect is lying or not, based only on the detector readings or only on behavioral signs. In Chapter 5, Basic Errors and Precautions, I explained the possible dangers of misinterpretation of behavioral signs and the precautions you can take to reduce them. In the same chapter I tried to clarify the dangers of interpreting the detector’s readings as the only evidence of a lie. A verifier should always evaluate the likelihood that gestures, facial expressions or detector readings can tell both lies and truth, and very rarely provide absolute certainty. In these rare cases, when the emotion expressed by facial expressions or the flow of words clearly contradicts all other indications, the suspect must be “poked into it with his nose” - and, as a rule, he is immediately recognized. But most often, the behavioral signs of deception (like a detector test) are only the basis for deciding whether to investigate further or not.
The verifier must also always remember that a liar may not be at all wrong. Some cheat so easily that it is impossible to notice any behavioral signs, and some - so hard that behavior errors - and hence the signs of deception - a lot. In the next chapter, we will look at cases where it is difficult to recognize a lie, and when it is easy to recognize.