You probably can’t tell when someone’s lying

Don’t show and don’t tell.
Don’t show and don’t tell.
Image: Reuters/Las Vegas Sun/Steve Marcus
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In poker, a”tell” is an unconscious cue that reveals something about a player’s hand. Players don’t always notice the signs they share about the cards they’re dealt and an observant opponent can pick up information by registering behavioral tics. But a cunning player can gain the upper hand yet again by tricking you with a supposedly telltale tic.

The same patterns appear to hold true in regular conversation as well. A recent study published in the Journal of Cognition argues that the cues we typically use to pick up on lies are deceptive and probably don’t reveal what we imagine they do. Psychologists from the University of Edinburgh in Scotland used a two-person interactive game to explore the production and perception of verbal and nonverbal cues to lying. They found a “surprising mismatch” between speakers and listeners, meaning that the listeners’ expectations regarding “tells” of lying didn’t actually correspond to true indicators of deception.

The researchers designed a game where one player—the “speaker”—knew the location of a “treasure,” and the second player—which they refer to alternatively as either the “guesser” or the “listener”—did not. The speaker was told to give the listener clues about where the treasure was located, but was also told they could lie at will. The guesser had to try to find the treasure based on the clues, which meant they had to assess whether the speaker was telling the truth or not. The players were in the same room, sitting at the same table, during the game, and researchers recorded the speech and movements of all 24 players involved in the experiment.

It turns out, guessers were not particularly adept at picking up on lies. Or, put another way, speakers were able liars, giving away few of the signs that guessers expected from a lie. When speakers were lying, they were actually less likely to produce the verbal and nonverbal cues that guessers associate with making false statements, such as hesitation, speech disturbances—saying “umm” and “ahh” for example— changes in pitch and rate of speech, blinking, looking away, or gesturing with their hands. In fact, pauses in speech were more often a sign of truthfulness, the researchers write. And hand and body movements were only very slight indicators of deception.

The good news, however, is that speakers were disinclined to lie. “We observed a general bias towards truthfulness,” the psychologists conclude. This corresponded to a similar inclination in guessers to believe what was said to them. And these findings support previous studies on deceptive speech that actually find a tendency towards truthfulness in human communications.

Notably, the researchers also tracked the players’ mouse movements during the game, which enabled them to determine just how quickly judgments of veracity were being made. Players were very quick to judge whether utterances were true or false, the researchers discovered.

But liars don’t act how we generally guess they will, maybe because they know what we think is a tell. “The results we observed suggest that a liar’s behavior is influenced not only by the act of conceiving a lie, but by the expectations that listeners may have regarding the speaker’s speech and gestures,” the study states. The study is small, so results should be taken with a grain of salt. The researchers say their findings highlight the importance of considering the “interactive dimension in lie production and lie perception paradigms” to better understand “the psychological dynamics that shape an act of deception.”

Still, umm, errr, you shouldn’t take my word for it. Perhaps play a game of cards to test your poker face and ability to discern a true tell—indicating a lie—from a lying tell.