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Who can catch liars?

catch liars

Lie detection and occupational groups

The ability to detect lying was evaluated in 509 people including law enforcement personnel, such as members of U.S. Secret Service, Central Intelligence Agency, Federal Bureau of investigation, National Security Agency, Drug Enforcement Agency, California police and judges, as well as psychiatrists, college students, and working adults. A videotape showed ten people who were either lying or telling the truth and describing their feelings. Only the Secret Service performed better than chance, and they were significantly more accurate than all of the other groups. When occupational group was disregarded, it was found that those who were accurate in catching liars apparently used different behavioral cues and had different skills than those who were inaccurate. You can read the full article here 

Lies happen everywhere

Lies occur in many arenas of life, including the home, school, and workplace, as well as such special contexts as in police interrogations and in courtroom testimonies. In low-stake lies, the liar suffers no more than embarrassment if caught, but in a high-stake lie, the consequences for success or failure may be enormous for both the liar and the liar’s target. Examples of such high-stake lies include those between heads of state during crisis, spousal lies about infidelity, the betrayal of secrets through espionage, and the range of lies involved in perpetrating various crimes.

Failure and errors in lies

Lies fail for many reasons. The lie may be exposed by facts that contradict the lie or by a third party who betrays the liar’s confidence. Sometimes, such outside information is not available or is ambiguous. Then the lie succeeds or fails solely, or primarily, on the basis of the liar’s behavior, which the legal profession terms demeanor.

Two types of errors in detecting lies may occur when truthfulness based on demeanor is judged. In a false negative, a liar is incorrectly judged to be truthful. In a false positive, a truthful person is incorrectly judged to be lying. In a high-stakes lie, either type of mistake can have serious consequences. In dealing with such situations it would be important- for the clinician, the jurist, the businessman, the counterintelligence agent, and so on- to know how much confidence should be placed in judgments based on demeanor (by layman or expert) about whether someone is lying or telling the truth.

People are not very good at detecting lies

The answer from 20 years of research is that people have not been very accurate in judging when someone is lying. In the usual study, observers are given video or audio recordings and are asked to judge whether each of a number of people is lying or telling the truth. Average accuracy in detecting deceit has rarely been above 60% (with chance being 50% ), and some groups have done worse than chance. Most of these studies examined college students, who may not have had any special reason to learn how to tell when someone is lying. Perhaps professional lie catchers, those whose work requires them to detect lying, would be more accurate.

Surprisingly, three studies of professional lie catchers did not find this to be so. Kraut and Poe (1980) found that customs officials were no more accurate than college students in detecting deceit in mock customs examinations. Depaolo and Pfeiffer ( 1986 ) found no difference between federal law enforcement officers, regardless of experience, and college students. Conkin ( 1987 ) found police officers did no better than chance when they judged videotapes of college students who had lied or been truthful in an experiment.

Ours is the first study to use behavioral samples drawn from a set of videotaped interviews that prior behavioral measurement showed differed when subjects lied or told the truth. Facial muscular movements measured with the Facial Action Coding System included more masking smiles when the subjects lied and more enjoyment smiles when they told the truth about their feelings. Vocal measurement also distinguished the lying and truthful interviews. There was an increase in fundamental pitch when the subjects lied. When both the vocal measure and the two facial measures were combined, it was possible to classify 86% of the subjects correctly as either lying or being truthful. Because there were known behavioral differences between the honest and deceptive samples, our studies could focus on the question of how well observers can detect deception.

In one of our groups, we were able to test how well subjects could recognize micro expressions, facial expressions that last no more than a fraction of a second. On the basis of our proposal that micro expressions are an important source of behavioral clues to deceit, our hypothesis predicted a positive correlation between accuracy in detecting deceit and accuracy in recognizing micro expressions of emotion. 

Why are some people more accurate in detecting deceit? 

Across our total sample, we found no relationship between accuracy and detecting deception and age, sex, or job experience. Within two groups, the Secret Service and federal polygraphers, age was negatively correlated with accuracy, with the most highly accurate observers (accuracy 80% or greater) being under 40 years of age. We found a sizable correlation between experience and accuracy only for the Secret Service. Experience and age were very highly correlated in this group. More experienced professionals typically are less involved in face to face interrogation and more involved with administrative duties, which may result in a decline in their skill and deception detection. Our findings suggest that accurate lie catchers used different information than did the inaccurate ones. They listed different and more varied behaviors, emphasizing nonverbal more than verbal ones, and also mentioning using both verbal and nonverbal, rather than relying on verbal behavior alone. Also, our finding that accuracy and identifying micro expressions was correlated with accuracy in catching lies suggests that in addition to informational differences, accurate observers may possess superior skills in spotting and decoding emotional information displayed on the face.

Why is the Secret Service better than other occupational groups?

There are a number of possible explanations. Many of the members of this group had done protection work, guarding important government officials from potential attack. Such work may force reliance on non verbal cues (e.g., scanning crowds), and that experience may result in greater attention to nonverbal behavior in our tests. Also, there may be a difference in the focus of their interrogations. The members of the forensic services division of the Secret Service when we tested spend part of their time interrogating people who threatened to harm government officials. Secret Service officials told us that most of these people are telling the truth when they claim that their threat was braggadocio, not serious. It is only the rare individual who was lying in his or her denial and actually intends to carry out such a threat. Members of the criminal justice community told an opposite story; They believe that everyone lies to them. Thus, the Secret Service deals with a much lower base rate of line and may be more focused on signs of deceit, whereas the criminal justice groups, with a higher base rate of lying, may focus more on obtaining evidence, not detecting lies. 

In discussing our findings with members of the other occupational groups, they suggested other explanations for their poor performance. The polygraphers claimed to focus on the polygraph exam itself, the preparation of the questions to be asked, and the reading of the charts. Many of them specifically disavowed tending to nonverbal behaviors, which in our test were the measurably discernible source of clues to deceit. Judges told us that they usually are seated in a position that prevents them from seeing the faces of those who testify, and are often focused on taking notes rather than attending to the nuances of behavior. They tend to pay most attention to the words the witnesses say, rather than to their behavior. Many psychiatrists claim not to be interested in lying, saying that patients will eventually reveal the truth to them. This is not so for those who do forensic work, and thus it was surprising that we found no difference between them and psychiatrists who do not do forensic work.

Our study demonstrated that some occupations (like the Secret Service) can catch liars more frequently (than what is seen in other professions); that the most accurate lie catchers report using both nonverbal and verbal clues to detect deceit; that these people are better able to interpret subtle facial expressions; and that in some occupational groups, the most accurate lie catchers are younger rather than older. Accurate lie catchers cannot be identified by either sex or their confidence in their lie catching ability. Some caution about these findings must be maintained, however, because they are based on judgments of only one kind of deception, the concealment of strong negative emotions.

Can you tell if someone is lying?

See how well you can detect deception by taking the lying quiz.


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