New directions in deception detection?

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Jessica Seigel, "The truth about lying", Knowable Magazine 3/25/2021

You can’t spot a liar just by looking — but psychologists are zeroing in on methods that might actually work

The featured research is a review by Aldert Vrij, Maria Hartwig, and Pär Anders Granhag, "Reading Lies: Nonverbal Communication and Deception", Annual Review of Psychology 2019:

The relationship between nonverbal communication and deception continues to attract much interest, but there are many misconceptions about it. In this review, we present a scientific view on this relationship. We describe theories explaining why liars would behave differently from truth tellers, followed by research on how liars actually behave and individuals’ ability to detect lies. We show that the nonverbal cues to deceit discovered to date are faint and unreliable and that people are mediocre lie catchers when they pay attention to behavior. We also discuss why individuals hold misbeliefs about the relationship between nonverbal behavior and deception—beliefs that appear very hard to debunk. We further discuss the ways in which researchers could improve the state of affairs by examining nonverbal behaviors in different ways and in different settings than they currently do.

That review focuses on why peoples' ideas about clues to deception are mostly wrong, and why nobody is very good at detecting deception from behavioral cues.

The Knowable article has some suggestions about ways to train interrogators to do better, but these better methods are not about non-verbal cues or other "tells", but rather about ways to get liars to trip themselves up in laying out content:

For example, interviewers can strategically withhold evidence longer, allowing a suspect to speak more freely, which can lead liars into contradictions. In one experiment, Hartwig taught this technique to 41 police trainees, who then correctly identified liars about 85 percent of the time, as compared to 55 percent for another 41 recruits who had not yet received the training. “We are talking significant improvements in accuracy rates,” says Hartwig.

Another interviewing technique taps spatial memory by asking suspects and witnesses to sketch a scene related to a crime or alibi. Because this enhances recall, truth-tellers may report more detail. In a simulated spy mission study published by Mann and her colleagues last year, 122 participants met an “agent” in the school cafeteria, exchanged a code, then received a package. Afterward, participants instructed to tell the truth about what happened gave 76 percent more detail about experiences at the location during a sketching interview than those asked to cover up the code-package exchange“When you sketch, you are reliving an event — so it aids memory,” says study coauthor Haneen Deeb, a psychologist at the University of Portsmouth.

The article doesn't examine the sad history of lie-detection technology, an industry that continues to take in millions of dollars from law-enforcement agencies and others, for devices that have no credible validation of performance.  Some earlier posts discussing that history:

"Analyzing voice stress", 7/2/2004
"BS conditional semantics and the Pinocchio Effect", 8/29/2004
"Determining whether a lottery ticket will win, 99.999992849% of the time", 8/29/2004.
"KishKish BangBang", 1/17/2007
"Industrial bullshitters censor linguists", 4/30/2009 (see especially the comments threads, e.g. herehereherehere.)
"Speech-based lie detection in Russia", 6/8/2011
"Speech-based 'lie detection'? I don't think so", 11/10/2011
"Reputable linguistic 'lie detection'?", 12/5/2011
"Linguistic Deception Detection: Part 1", 12/6/2011
"More deceptive statements about Voice Stress Analysis", 5/18/2014
"PR push for 'Voice Stress Analysis' products?", 4/24/2017

Update — the Knowable article also appears in The Atlantic magazine, as "You’ve Been Lied to About Lying", 3/27/2021.


  1. mg said,

    March 28, 2021 @ 11:54 am

    These false ideas about non-verbal and verbal clues about lie detection do so much damage to innocent people, starting in childhood when teachers and school administrators use them to decide that innocent kids must be lying – especially children from other cultures or with disabilities such as autism.

  2. Laura Morland said,

    March 28, 2021 @ 12:51 pm

    This article is well-timed, because I ran across a number of comments on YouTube referring to an "authoritative" website where so-called experts had analyzed Meghan Markle's body language during her famous Oprah interview earlier this month. Apparently the "authorities" behind this website determined that she was lying something like 85% of the time!

    I refuse to click on the referenced site, but it just goes to show how "non-verbal behavior experts" themselves can exhibit behavior not far from that of conspiracy theorists.

  3. kltpzyxm said,

    March 28, 2021 @ 5:26 pm

    That is pretty cool. I also famously avoid clicking on referenced sites for safety reasons, unless they seem especially safely or relevant.

  4. AntC said,

    March 28, 2021 @ 7:22 pm

    those asked to cover up the code-package exchange

    Asking to cover up hardly seems an effective way to make a liar. We're presumably trying to detect practiced/persistent/habitual liars, with strong motive for deceiving.

    So the experiment with police trainees seems stronger evidence. I rather thought withholding critical knowledge was already a police technique — going by detective novels and procedurals on TV.

  5. Rick Rubenstein said,

    March 28, 2021 @ 9:10 pm

    Isn't it sufficient to check whether their vector space has an alternating bilinear map that satisfies the Jacobian identity? (Sorry. Also don't ask me to do any real math; I looked it up on Wikipedia.)

  6. Cervantes said,

    March 29, 2021 @ 7:07 am

    I have noticed that on the TV police procedurals, actors often convincingly portray liars so that the viewer thinks, "that guy is lying." It's evident that's what the director wanted. Somehow we have an expectation of what a liar ought to look and sound like that an actor can present.

  7. KeithB said,

    March 29, 2021 @ 8:47 am

    But taking a lie detector test is so much *fun*. I enjoyed mine. I did tell them that I had taken pens from work though, just in case.

  8. stephen said,

    March 30, 2021 @ 3:16 pm

    Let's test the lie detection methods on the "experts" while they discuss their lie detection techniques.

    Let's attach lie detectors to actors while they are performing in a stage play, or for movies or TV…let's stop there. I understand the results would be unreliable–but interesting.

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