We think we know how to catch liars, but according to research released over the last year or so, we really do not. We’ve picked up bad information from movies and television and even some unreliable "scientific" sources. So what do the scientists really say about what is and isn't valid when trying to catch a liar?
Three Things You Thought Were Giveaways But Are Not Always So:
1. Bad Eye-Contact: The inability to maintain steady eye contact when being questioned was always considered a sure sign that someone was lying. Not necessarily so, argues criminologist and professor Par-Anders Granhag. People avert gazes for any variety of reasons including just discomfort, distraction, and even neurodivergencies.
2. Nervousness/Shakiness: As Dr. Julia Shaw has pointed out, about 70% of researchers have stated that a guilty or lying individual is not necessarily likely to be any more nervous or fidgety than a truth-teller.
3. Constantly Shifting Posture/ Touching Themselves Often: Once considered a sign of excessive self-awareness because of uncertainty, again this has been shown to be an unreliable indicator. Many reasons exist why people exhibit discomfort and awkwardness, but that does not mean they are lying.
So How Do You Catch Liars?
As professor Aldert Vrij has repeatedly indicated, relying on non-verbal cues remains an unreliable indicator of lying. They key remains in the spoken language – what is said and how it is said. Specifically:
1. Liars Give Less Details: Over 70% of researchers agree that liars are less likely to give details around any issues.
2. No complications in the Story: Life is complicated and we all have unexpected issues that come in the span of the day in executing any undertaking – random people show up (or don’t), scenarios change, complications arise. If someone’s story has none of these and flows perfectly with no fluctuations, that remains a tad suspect.
3. A Story that Shifts in the Face of Discrepancies: This is what researchers Granhag and Timothy Luke present as a Shift of Strategy (SoS) approach. You do not directly accuse the individual of lying, but present small discrepancies in their stories that contradict what they said. If they cannot explain the differences or do not 'fess up to an error and instead opt to change their stories, that suggests that they are lying.
4. A Change in the Language: Dr. Sophie van der Zee and her colleagues conducted research that is widely gaining popularity that suggests the language we use (specific words and terms) change when we lie. As was reported, "Using a fact-checked database of tweets by Donald Trump, they found that the language he used when he lied was systematically different from his truthful tweets. One they made a personalized profile, the scientists could predict whether his tweets were true or not with an accuracy of 74%."
All this suggests that it's not necessary the visual cues but the verbal ones that best indicate truthfulness.
