The Unconscious Mind Can Detect a Liar – Even When the Conscious Mind Fails

UC Berkeley Haas School of Business study finds people may have some intuitive sense to tell when someone is lying

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Citations Psychological Science, March

Newswise — UNIVERSITY OF CALIFORNIA, BERKELEY'S HAAS SCHOOL OF BUSINESS –When it comes to detecting deceit, your unconscious instincts may be more accurate than conscious thought when making judgments about others, according to research by Leanne ten Brinke, a postdoctoral fellow at the University of California, Berkeley’s Haas School of Business.

In the paper, “Some Evidence for Unconscious Lie Detection,” published in Psychological Science (online March 21, 2014), the authors find that conscious awareness may hinder our ability to detect whether someone is lying, perhaps because we tend to seek out behaviors that are supposedly stereotypical of liars, like averted eyes or fidgeting. But those behaviors are not indicative of an untruthful person.

“We set out to test whether the unconscious mind could catch a liar – even when the conscious mind failed,” says ten Brinke. Along with Berkeley-Haas Assistant Professor Dana R. Carney, lead author ten Brinke and UC Berkeley graduate Dayna Stimson (BA 2013, Cognitive Science), hypothesized that these seemingly paradoxical findings may be accounted for by unconscious mental processes.

“Our research was prompted by the puzzling but consistent finding that humans are very poor lie detectors, performing at only about 54 percent accuracy in traditional lie detection tasks,” explains ten Brinke.

That’s hardly better than chance, as if participants were simply guessing whether the person was lying. And it’s a finding that seems at odds with the fact that humans are typically sensitive to how others are feeling, what they’re thinking, and what their personalities are like. Further, it doesn’t make evolutionary sense that humans evolved no ability to accurately detect deception.

The researchers first asked 72 participants to watch videos of “suspects” in a mock-crime interview. Some of the suspects in the videos had actually stolen a $100 bill from a bookshelf, whereas others had not. However, all of the suspects were instructed to tell the interviewer they had not stolen the money. In doing so, one group of suspects was lying, whereas the other group was telling the truth.

When the 72 participants were asked to say which suspects they thought were lying and which were telling the truth, they were often wrong. They were only able to detect liars 43 percent of the time and truth-tellers only 48 percent of the time.

But the researchers also probed participants’ more unconscious instincts about the suspects with widely used measures of less conscious mental processes. Such measures are able to tap into the extent to which a word or idea is active in one's mind. The Berkeley-Haas researchers tested whether seeing someone tell a lie would activate lie-related concepts and ideas in the mind. Likewise, when one sees someone telling the truth, do concepts and ideas associated with the truth become active in one's mind?

Using reaction time measures, results showed that participants responded more quickly to deception-related words (e.g. “untruthful,” dishonest,” and “deceitful”) when they were thinking of suspects who were actually lying. At the same time, participants responded more quickly to truthful words (e.g. “honest” or “valid”) when thinking of suspects who were actually telling the truth.

The findings provide evidence that people may have some intuitive sense, outside of conscious awareness, that is able to tell when someone is lying.

“These results provide a new lens to examine social perception and suggest that – at least in terms of lie detection – unconscious measures may provide additional insight into interpersonal accuracy,” says ten Brinke. Although further work is needed before the practical implications of these findings will become clear, this insight represents one aspect of a research program led by ten Brinke and Carney which aims to uncover some of the simple, effective, and free strategies ordinary people can use to better detect lies in their daily lives.

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