Esperanza Aguirre used to say that “lies have very short legs” making use of one of the keys that the rich proverb we have in Spain offers us to recognize liars, who are also caught in front of “a lame man”. However, lies are not always so easy to spot. In fact, there are people who are trolling experts who don’t arouse our suspicions, which is why science wanted to ask about it. the keys to detecting a lie without using a polygraph.

A study of University of Amsterdam addressed the way in which the lie can be discerned from the truth in a story only with look at the level of detail that people give us when telling a story. So, generally speaking, researchers need more data and descriptions to reveal who, what, when, how, and why they are more likely to be telling the truth. If they ignore them, they are probably lying.

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With this simple test, deception can be detected with an accuracy of nearly 80%. 9/11 also marked a milestone in behavior detection training, and airport security personnel across the United States were trained to look for 92 clues that indicate a person was cheating on them. Polygraphs, in turn, combine physiological data such as blood pressure, heart rate and breathing to make a complete picture that specialists interpret.

Drop tracks instead of adding them

However, research shows that even trained professionals don’t have an easy time interpreting data on the fly and concluding whether someone is lying or not. Forensic psychologist and lead author of the study, Bruno Verschuere, assumes that this is an “impossible task, since people cannot evaluate all these signals in a short time, much less integrate several signals into an accurate and true judgment”. It also explains that people have assumed stereotypes about others and influence judgment.

Seeking to overcome these problems, Verschuere and his colleagues decided to try a “radical alternative”, instructing participants in their study to focus on one cue and ignore all others: the level of detail in a testimony. “Truth can be found in simplicity and we propose discard rather than add clues when trying to detect fraud“, deepens the expert.

He and his team set up nine studios to train 1,445 people to guess whether handwritten statements, video interviews and transcripts, and live interviews about college students’ activities on their campus were true or false. The testimonies were collected from young people who had been related to a simulated exam robbery and lied about it or witnessed it while walking through the premises without knowing the ruse.

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Among those tasked with discern between reality and false narrative, some relied on their intuition to detect lies or used too many factors when making a decision, so conclusions seemed randomly chosen. In contrast, members of another group who were instructed to focus only on the level of detail were able to separate truth from lies with 59 to 79% accuracy.

human polygraphs

Specifically, the research team was asked to examine the “degree to which the message included details such as descriptions of people, places, actions, objects, events and their time”, in addition to the degree to which the testimony appeared complete, concrete, powerful and rich. in detail: “Our data show that relying on one good signal can be more beneficial than using too many. signs,” says Verschuere.

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The team’s rule of thumb for using this determinant and ignoring the rest was superior lie detection, regardless of whether participants knew the purpose of the activity, ignoring that they were being some kind of human polygraph. This aspect suggests, says Verschuere, that pre-existing stereotypes of guilt and innocence didn’t get in the way in the use of the level of detail as a detection tool.

In borderline situations, people are likely to enrich lies with details to increase their credibility; therefore, general lie detection rules may depend on context, researchers say. However, the use of more cues and even the Big Data and machine learning approach would not improve the accuracy in detecting these lies, they conclude: “To deal with information overload it’s better to ignore. Sometimes less is more.”

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