Most people believe that they are pretty good at knowing when other people are lying. But research clearly shows that people are notoriously bad at detecting others’ lies. Even the very best lie detectors are only slightly better than chance (despite what might have been portrayed on the show Lie to Me).
Here are 5 reasons why people aren’t very good lie detectors:
1. We Rely on Stereotypes. And these stereotypes aren’t always accurate. For example, most people will use lack of eye contact as a cue of deception, but our research found that liars actually engaged in more eye contact, presumably in an effort to look more truthful. We also believe that cues of nervousness (fidgeting, wringing hands, sweating) are associated with deception, but sometimes people display these cues for reasons other than deception.
2. We Have a Trusting Bias. Research shows that we have a sort of “default” mechanism that makes us tend to believe that most people are telling the truth. Even in studies where participants are told that half of the people are lying, they judge the majority of them as honest. [This holds unless you are a police officer, customs agent, or work for the Secret Service — they tend to have a mis-trusting bias default.]
3. Some People Just Appear More Honest or Deceptive. There are individual differences in nonverbal expressive style that lead some people to look more honest and others as more dishonest. This is called the “demeanor bias.” Persons who are emotionally expressive and who move and speak more freely and fluidly are judged honest. Those who are stoic, with hesitant, staccato speech styles are seen as more dishonest.
4. We Don’t Get Much Feedback About Our Detection Accuracy. As a result, we aren’t able to hone our detection skills. We might think someone is lying, but if we don’t actually find out whether it was a lie or a truth, we aren’t able to learn to get better at detection.
5. We Simply Get Out-Foxed. Deception is a complex social interaction, much like a dance or performance. The very best liars know how to look honest (demeanor bias), they monitor their behavior, rehearse their answers, and study the detectors’ nonverbal behavior to see if they are suspicious or gullible and adjust accordingly.
So, how can you be a better deception detector?
1. Don’t Be Gullible. Recognize the trusting bias in yourself. Don’t assume that everyone is telling the truth (but don’t become overly suspicious). Don’t rely solely on simple cues (he’s avoiding eye contact; she’s stammering).
2. Analyze. Contrary to what many believe, verbal cues are often the best way to detect deception. Consider the plausibility of the story. Does it make sense and seem reasonable? Notice discrepancies in behavioral styles, from known truth-telling episodes, rather than focusing on specific cues.
Bond, C.F., & DePaulo, B. (2006). Accuracy of deception judgments. Personality and Social Psychology Review, 10, 214-234.
Ekman, P. (2001). Telling lies. New York: Norton.
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