How to Catch a Liar

The truth is in the details -- but you have to listen hard.

By Shannon Rupp 22 Nov 2014 |

Shannon Rupp was a Tyee contributing editor. For permission to reprint this article please contact the author: shannon(at) 

Well I'm glad that's over. Between the civic elections and the Jian Ghomeshi scandal, it seems this fall's theme has been "Lies, damn lies, and press releases."

Or perhaps that's redundant?

People lie all the time, of course, so I'm not sure why I've found the last couple of months so irritating. Depending on the research study, the average person tells anywhere from 1.65 lies a day, to one every 10 minutes, to between 10 and 200 lies a day. Many studies find that men lie far more often than women. Others find they lie differently: men lie to protect themselves, while women lie to protect others, so they specialize in those white lies necessary for smooth social interaction. Although I suspect if you dug into that research, you'd find that those lies are not gender-based at all but a reflection of the subjects' working environment.

As someone who interviews people, I've long had an interest in how you can determine who is lying. The short answer is that you can't. Well, not just by looking. The key is fact-checking, which is why journalists used to be valuable -- in another era, they tested statements for accuracy before they published them, rather than just acting like stenographers.

Still this is the era of smartphone videos and plenty of people who believe they can read body language the way psychics read auras. A guy named Paul Ekman did research in the 1970s that suggested people's "micro expressions" reveal deception. His work gained popularly via the TV show Lie To Me. But other researchers have never been able to replicate his findings that a slight curl of the lip or a lift of a shoulder is the equivalent of what poker players call a tell. Still, Ekman's consulting firm works with law enforcement of all stripes and his views are incorporated into courses for them on how to read body language.

Because of the widespread belief that mannerisms betray inner thoughts, spies, politicians, celebrities -- and quite possibly, terrorists -- are coached to appear trustworthy. Meanwhile, Ekman's work hasn't been peer reviewed for more than 30 years. In 2010 he explained to Nature magazine that he hasn't published the research on his hypotheses for decades now to keep his findings from America's enemies.

Maybe. But his words don't pass the science world's sniff test for truth. If you can't repeat the results of a study, intelligent people accept that it's mistaken. And if you're reluctant to have your research subjected to double-blind tests, I'd say that's a pretty telling fact.

Ironically, Ekman's quote also illustrates something researchers have known for a long time: words are more revealing than mannerisms.

Andy Morgan, a forensic psychologist at Yale University who researches memory and deception, says that a liar's effectiveness also relies on the willingness of his audience to believe him. Liars will paint the broad suggestive strokes of a story, but they lack telling details.

"What we tend to do when people tell us lies is that we fill in the blanks," Morgan told the Criminal podcast earlier this year in an episode called "Pants on Fire."

I recalled Morgan's work when I saw the online enthusiasm for Jian Ghomeshi's inept Facebook post that paved the way for his public shaming. Journalists were all joking about the former CBC host paying a "crisis communications" firm $600 an hour to write the clumsy rhetoric that removed any protection he might have had from defamation laws.

Believers want to believe

Ghomeshi's claim that CBC fired him for kinky sex practices looked like an obvious lie to me and most of my reporter and lawyer pals because it didn't even pass the simple fact-check. Mainstream TV shows have been making sly quips about BDSM sex for at least 25 years and it's widely featured in all sorts of pop culture. That means it's uncontroversial. So, obviously, something else had to be going on to cause a fallout between the celebrity interviewer and the public broadcaster -- and Ghomeshi's foolish statement opened the door to what it might be. (Three women have made abuse allegations against Ghomeshi to Toronto Police, but he has not been charged.)

And yet tens of thousands of people believed Ghomeshi because they wanted to believe him. They enjoyed his interviews. Because radio is such an intimate medium, they felt like they knew him. To their way of thinking, he was a friend. And it's downright churlish to fact-check your friends.

As Morgan notes in the Criminal interview, it's things like this that make human beings remarkably bad at determining who is lying. We're distracted by emotions and beliefs so we don't really hear what people are saying.

Morgan works with the FBI, police, military, and other groups keen on lie detecting, and he says that investigators often have an exaggerated sense of their own talents when it comes to spotting deception. When tested, they're right about 50 per cent of the time. In other words, they're about as accurate as flipping a coin. Which is about as accurate as a polygraph. That's because polygraphs also rely on the physical clues that supposedly betray lying.

It's true that sweaty palms, a racing pulse, and an eye tic reveal anxiety and stress -- but they don't reveal what the stressor is. That twitchy guy in the airport might be a hijacker, but more likely he's a white-knuckle flyer who is about to have a really unpleasant encounter with security.

So where does that leave juries, voters, and the rest of us looking for a little integrity in communications?

Listen to discern truth

Well, apparently, if we interview people thoroughly and genuinely listen to what they're saying, we have a better chance of discerning the truth.

Researchers have found that asking someone to recall details with "cognitive interviewing" techniques that include seemingly irrelevant questions about sense memory will yield a fairly accurate predictor of whether a story is true. Interviewers ask subjects to recall an event and then asked them to remember what they smelled at the time? What did they hear, see, feel, think...?

The sensory prompts can turn up valuable details that witnesses might not otherwise mention. And those kinds of questions can reveal gaps in the picture they're painting. As Morgan's research has found, deliberate liars worry about being consistent, so they tell the same simple story, using the same words, over and over again. Asked for additional irrelevant details, their imaginations will usually come up short.

"It's like comparing a digital photograph of your house to a child's drawing of the house," Morgan says.

But even more telling is a computer analysis of those interviews. Liars inventing a story respond to questions with fewer words overall and less variety in the words. In Morgan's study, computer analysis of the stories found those patterns and detected a lie about 80 per cent of the time. Meanwhile, the professional investigators rating the same storytellers still had no better than a coin-flip's chance of spotting deception -- they were right about 54 per cent of time.

'True Believers' are scourge of truth-seekers

People: we're really, really bad at spotting liars with body language. Give it up!

As for the other 20 per cent of the interviews, the ones who fooled the computer analysis, I suspect they're probably in that category of liar that is impossible to uncover because they believe what they're saying. I call them True Believers, and they're the scourge of the information-seeking trades.

True Believers are the sort of witnesses who swear that the car speeding off from the hit-and-run was silver (when it was, in fact, black). They're cousins of that person who swears up and down she was rescued by an angel and, like Joan of Arc, has a remarkable amount of sense memory about her interaction with the heavenly being.

They're probably married to the witnesses who always say of their neighbours who turned out to be homicidal maniacs, "He was a quiet man."

They're not lying. Like Mulder in the X Files, they believe. But that doesn't mean we should.

When it comes to a successful lie, the liar is only half the problem: it takes a gullible listener to make a lie a reality.

So perhaps what irritated me most about this season of lies and press releases wasn't the lies, or even the liars, it was the fools who fell for them.

© Shannon Rupp. For permission to reprint this article please contact the author: shannon(at)  [Tyee]

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