A droopy head can reveal discouragement, a furrowed brow can mean concentration, and an upward glance can indicate boredom. Or perhaps these actions reveal none of those things. Despite this uncertainty, a cottage industry has sprung up starring analysts and consultants who purport to know what a person is thinking based on nonverbal cues. But while they may lack the intentional fraud of psychics, their success record is not much better.

Astrophysicist Ramin Skibba wrote about this in an article for Undark and he cited an example of a language consultant who interpreted Joe Biden’s downward look at his podium as withdrawal. Or possibly a sign of self-control. These contradictory interpretations give the claimant wiggle room and are akin to horoscopes. Another commonality with astrologers is telling a person what they want to hear. For example, the president’s people would be told Biden was exhibiting this self-control, while the opponent’s team would be told he had been beaten into submission.

No real harm would be done in these cases. By contrast, a self-described body language expert being trusted by police officers, airline screeners, and federal agents to gauge truthfulness can be unsettling. A suspect wrongly deemed to be prevaricating, a Muslim would-be traveler, or a job applicant falsely accused of lying about past deeds could have serious ramifications for the victim.

Most assertions by body language interpreters have yet to be tested by science in a controlled setting. For example, Skibba wrote, “Claims that a single gesture reliably indicates what a person thinks or desires are not backed by solid evidence.” It is a patchwork of guesses, assumptions, and whim.

It is true that research teams have looked at how the brain reacts to facial expressions and how newborns imitate adult gestures. But scientists have also discovered that body language can be complex and granular, making solid declarations of what certain gestures mean to be challenging at best. Skibba quoted University of Idaho communication researcher Dawn Sweet, who informed him, “There’s not likely to be a single behavior diagnostic ever to be found” to indicate if someone is untruthful or experiencing a specific emotion.

Sweet prefers to look at someone’s body language and spoken words together, since they often say the same things. She and her fellow researchers also examine if the body language is consistent for them or an outlier.
Sweet cites a meta analysis of studies centering on 1,300 estimates of 158 possible deception signs. The studies focused on cues people might associate with lying, such as looking down or quickly botting their head. Researchers found such cues have little connection to whether a subject is lying. A person might appear uncomfortable at a given moment, but observers rarely know why. It could be dependent on the situation, person, and culture.