The great trial lawyer, Gerry Spence, said that we all have “psychic tentacles” that reach out from us and serve us in the detection of credibility and authenticity. Says Spence, “Like our immune system, our invisible credibility detectors are constantly searching for the enemy, for the thin clank of the counterfeit.”[1] It seems we generally experience the detection of the “counterfeit” as either detections of outright lies or things we find merely insincere. For instance, there does seem to be some difference in the insincerity of saying “I like your new haircut” though we don’t truly mean it, versus saying “I didn’t kill Jules Epstein” even though we’ve just secreted his body under the shed in our backyard. Researchers seem to agree that both are forms of lies but call the former insincerity a “prosocial” lie.[2] A greasing of the skids in our social graces. The question I wanted to explore this month tees up an upcoming blog piece by my quite-alive-and-lively co-conspirator, Jules Epstein. His blog will look at expressions of gratitude—and I’ll leave it at that to avoid spoilers. This month, I’m going to share a study about lie detection, based only on nonverbal cues, that pitted seasoned detectives against other subjects who don’t necessarily lie detect for a living.[3]
Before I describe the experimental set-up the researchers employed, it’s essential to point out that there is a whole host of research out there proving which nonverbal cues are associated with deception and which nonverbal cues are thought to reveal a lie but don’t show any statistically valid association with lying at all. The authors of this study review the proven cues versus the suspected cues quite thoroughly before walking through the details of their experiment.[4] Armed with data about which nonverbal cues really do and really don’t reveal a lie, the researchers gathered for their test a host of presumptive lie detection experts: police detectives, customs officers, patrol officers, and prison guards. 93% of these experts “…indicated that they had considerable experience with detecting deception.”[5] Their opponents in this test of skill would be incarcerated prisoners and college students.
The authors used a total of 16 nonverbal cues for this test. Some of these 16 are experimentally proven indicators of lying: use of a higher pitch, a decrease in leg movement, and slower speech rates, for example.[6] However, some of the cues used in the experiment are merely believed to indicate deception, but have no provable correlation to lying: averting one’s gaze, trunk movements, and self-touching actions are examples of this sort. All 16 nonverbal cues were placed in a series of multiple-choice questions to test whether the subjects would correctly identify deception behaviors or would show they’ve been relying on statistically invalid nonverbal cues to sniff out deception.[7] So, for instance, a question might offer a series of choices about whether liars self-touch more than truth-tellers, self-touch less than truth-tellers, or, neutrally, self-touch just as much or as little as truth-tellers.[8]
Let’s get to the results, shall we? Who are the best lie detectors—if we judge them all on which group most accurately relies on the proven cues of deception? In such an experienced group, it’s probably not the college students. Let’s get that out of the way. What about the customs agents? Surely, they have had a ton of practice. “No, officer, I didn’t smuggle any wildlife into the country with me,” Tommy Traveler says while vigorously tugging on his earlobe. Meanwhile, a duck-billed platypus is wriggling free from Tommy’s L.V. bag. And yet, it’s not the customs agents either. The patrol officers? Nope. You guessed it. It was the prisoners. But why? The researchers theorized that a prison environment would provide many more opportunities for prisoners to see deception from others and receive feedback on their assessments of deception.[9] The researchers further posited that being a good lie detector mattered much more in prison given that “Being successful in such a world depends on the ability to tell when you’re being lied to.”[10]
[1] Gᴇʀʀʏ Sᴘᴇɴᴄᴇ, Hᴏᴡ Tᴏ Aʀɢᴜᴇ Aɴᴅ Wɪɴ Eᴠᴇʀʏ Tɪᴍᴇ 49 (1995).
[2] See, Karyn Fish, Kathrin Rothermich & Marc D. Pell, The Sound of (In)Sincerity, 121 J. PRAGMATICS 147, 148 (2017).
[3] Aldert Vrij & Gün R. Semin, Lie Experts’ Beliefs About Non-Verbal Indicators of Deception, 20 J. NONVERBAL BEHAV. 65 (1996).
[4] See Id. at 65-67.
[5] Id. at 68.
[6] Id. at 65.
[7] Id. at 69.
[8] Id.
[9] Id. at 67.
[10] Id.