Study reveals flaws in key training tool for detection of security lies

Developed by an influential American psychologist, the Micro-Expressions Training Tool, or METT, inspired the famous television show Lie to Me, which revolved around the supernatural ability of its main character to tell the truth of the fake by analyzing tiny tics of face. And in the real world, METT is used to train airport staff to detect people with potential safety risks.

But a research project involving a professor from Huddersfield University concluded that training at the METT did not improve the detection rates of lies beyond the levels that can be reached by conjecture.

The verdict is reported in a new article that concludes that METT's failure is very problematic "since training in micro-expression recognition is a big part of a filtering system that has become more and more omnipresent in the security of our aviation ".

The METT is now part of the SPOT system (passenger screening system) used for airport security in the United States. This meant that research on its effectiveness was essential, say the authors of the article.

One of them is the cognitive psychology reader from the University of Huddersfield, Dr. Chris Street, who specializes in the detection of lies. He formed a collaboration with colleagues from two American universities who had decided to perform the first comprehensive test known to METT as a lie detection tool.

The results are revealed in an article published in the Journal of Investigative Psychology and Offender Profiling.

The people trained at METT did not do better

METT was developed by psychologist Dr. Paul Ekman, whose research group was the inspiration for the television series Lie to Me, with Tim Roth. It is a form of training that aims to improve the detection of micro-expressions: sadness, anger, fear, disgust, contempt and happiness. Ephemeral expressions can last as little as half a second.

"Recognizing micro-expressions can be helpful in better recognizing facial expressions, but it is more important to promote it as a way to detect deception," according to the new article, which later states that his research "does not give a optimistic picture of the utility of METT ".

The article describes the research process in which 90 students from an American university participated. Some were randomly selected to receive METT training and others received "placebo" sham training or none at all. They were shown stimulation videos containing truths and lies from five different deception detection studies. One of them was developed by Dr. Street and his colleagues.

The success rate of participants telling the truth from lies was then compiled. One of the conclusions was that METT-trained individuals did not perform better than those who had received fictitious or non-existent training, and that they were even worse than chance – "guessing would have produced results." slightly better ".

Commenting on the research project, Dr. Street said, "Most people in the field felt that the METT did not really care, and the Ekman group says that these micro-phrases help you detect the lies. There was not one, the problem is that it has now been used by the US government "