Reading The basic human emotions are the same in every culture in the world, according to the American psychologist Paul Ekman. Expressing these feelings are also expressed in the corresponding facial expressions that Ekman has put together with colleagues in an atlas. Even if people try to hide their true feelings, so-called micro-expressions - lightning-fast signs of emotion rushing across the face - can betray liars. "Science knows enough about what it looks like to be lying. It would be negligent not to use this knowledge. " This is the credo of US psychologist Paul Ekman. In decades of systematic research, the 74-year-old himself has developed much of this knowledge - knowledge that is now being used to detect suspects in airports or detect them in interrogations when the interviewee deviates from the truth.

With his know-how, Ekman has built a small empire: the Paul Ekman Group, a company that teaches secret services, police and embassies in seminars with videos and photos, role-plays and computer tests, what a human being with something to hide looks like, The courses are popular: A five-day training amounts to a proud $ 35, 000, reports the science magazine "Bild der wissenschaft" in its August issue.

The gentleman residing in a villa in the Oakland Hills near San Francisco has a mission and its motives go back to his childhood. His father, a doctor in the US Army, was prone to violence, his mother committed suicide when Ekman was 14 years old. "That's what shaped me. I wanted to do something, "recalls Ekman in an interview with" bild der wissenschaft ". Ekman studied psychology and has spent nearly 60 years studying human emotions and their expression and control.

The decisive step in his career was a journey Ekman made in 1966 into the jungles of Papua New Guinea. There he shows photos of faces in people living in Stone Age cultures. For example, interviewees were asked to choose from several portraits the image of a person whose child had just died or who showed someone at the sight of a decaying wild boar. The results did not differ from those expected in subjects from the modern Western world. display

The basic human emotions are universal and are reflected in a corresponding mimic, concluded Ekman from the results and developed a system of feelings: anger, surprise, fear, joy, disgust, grief and contempt are in all cultures in identical facial expressions. From these findings, Ekman and colleagues developed the Facial Action Coding System - FACS for short. This atlas of emotions with hundreds of photos shows all conceivable facets of human facial expressions and assigns these so-called Action Units (AU). These action units correspond to facial movements performed by one or more muscles. The curling of the nose, for example, corresponds to AU 9.

Combinations of the total of 44 possible AUs give rise to facial expressions. Thus, a happy face is made up of a combination of AU6 and AU 12, namely when the eye muscle is contracted at the same time and the corners of the mouth lift. The FACS has been used by medical professionals and psychologists for many years. The evaluation is still done in painstaking detail, but could soon be done automatically by computers, announced Ekman.

Such face scanners could then support Ekman's and his staff's trained human face readers, such as those currently stationed at 14 American airports under a program called SPOT. The task of the security staff is to identify suspicious people from the stream of travelers using a list of 35 criteria. Ekman does not want to reveal the exact criteria and the size of the hit rate - the danger is too great if this knowledge gets into the hands of terrorists, the psychologist explains in "bild der wissenschaft".

An important phenomenon in recognizing hidden feelings can be the so-called microexpressions discovered by Ekman: For a fraction of a second, expressions then flit across the face of the respective human being, which shed light on his true state of mind. Ekman has already collected countless examples of such micro-expressions, including such celebrities as OJ Simpson during a trial, or Bill Clinton during the election campaign. Only a good four percent of all people are such good liars that their body does not give such tell-tale signals, estimates Ekman.

In contrast to the rules of the SPOT program, he has made no secret of his system for detecting microexpressions and has even published a training CD-ROM. Nevertheless, the technology is by no means a universal means, for example, against lies and false statements in court, Ekman stresses and explains this with the example of
Othello: The hero Shakespeare killed his wife Desdemona because he saw fear in her face and concluded that she had betrayed him and now feared the revelation of this supposed secret. In fact, she was only afraid that he would not believe her.

Such situations can also arise when questioning witnesses or defendants, which can lead to wrong conclusions and wrong judgments, Ekman explains in "Bild der wissenschaft". "The fear of not being credible and the fear of getting caught look the same. Fear is fear. "

=== Désirée Karge: "The Living Lie Detector" bild der wissenschaft 8/2008, p. 16 ddp / science.de - Ulrich Dewald

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