Vincent Denault and his colleagues have been doing remarkable work informing the public and the scientific community about the pseudoscientific nature of a lot of popular techniques to decode “nonverbal language”.
I was lucky enough to contribute a tiny, tiny bit to their latest publication.
Here’s an excerpt from the abstract (emphasis mine):
“The objective of this article is to examine (i) concepts of nonverbal communication conveyed by these programs, methods and approaches, but also (ii) the consequences of their use (e.g., on the life or liberty of individuals). To achieve this objective, we describe the scope of scientific research on nonverbal communication. A program (SPOT; “Screening of Passengers by Observation Techniques”), a method (the BAI; “Behavior Analysis Interview”) and an approach (synergology) that each run counter to the state of science are examined. Finally, we outline five hypotheses to explain why some organizations in the fields of security and justice are turning to pseudoscience and pseudoscientific techniques. We conclude the article by inviting these organizations to work with the international community of scholars who have scientific expertise in nonverbal communication and lie (and truth) detection to implement evidence-based practices.”
You can read the English-version of the article here: https://www.researchgate.net/publication/332246373_The_analysis_of_nonverbal_communication_The_dangers_of_pseudoscience_in_security_and_justice_contexts