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Lie Detectors


By Dan Gordon '85

Published Oct 1, 2011 12:00 AM

George Washington couldn't tell a lie, but the rest of us have no such inhibition. Who couldn't use a foolproof way to spot a spouter of falsehoods? There are reliable red flags that pinpoint when someone is being devious or untruthful. Here's how to catch a liar in the act.


Illustration by Laurie Rose Nwald.

In the long-running TV game show To Tell the Truth, panelists questioned three contestants who claimed to be the same person, in an attempt to weed out the impostors and win the game. That was just for fun. But if you're a cop, a lawyer, a parent or spouse, the ability to tell whether someone's talking straight or not has real-life value. You might even think you're pretty good at it. But unless you've been specially trained, you probably aren't as good as you think you are, suggests Edward Geiselman, UCLA professor of psychology. But he can help.

In the early 1980s, Geiselman and colleagues began applying the principles of cognitive psychology to develop an approach, known as the cognitive interview, which is now widely used by detectives in questioning crime victims and witnesses. Several years ago, with funding from the U.S. Department of Homeland Security, Geiselman's team embarked on studies to identify reliable indicators of deception — verbal and behavioral.

Geiselman recently put his skills to the test by watching eight rounds of old To Tell the Truth shows on YouTube as part of a group of viewers. He correctly picked out the truth-teller in seven of the eight. The unschooled members of the group did not fare nearly as well.

"Detecting deception in someone else is not an easy thing to do," Geiselman says. "The typical person who is untrained barely does better than chance."

In His Own Words

Professor R. Edward Geiselman explains how to detect deception.

From UCLA Newsroom on May 18, 2011.

Still, you can learn to be a top-notch lie detector. Read on for tips on how to tell if a person is fibbing. But make sure you read to the end for Geiselman's disclaimer.

Just the (Non)-Facts

One of the most common misconceptions about deceptive people is that they will offer up a detailed account in an effort to convince the listener of their veracity. In fact, it's usually the opposite. "Deceptive people don't want to tell you very much," Geiselman says, "and when you ask them to elaborate, they give you the minimum in response to your request." When a liar is asked if he wants to add anything to his story, he is liable to quickly say "no," whereas the truthful person will at least give the question some thought. Similarly, made-up stories tend to lack detail and context, such as visual images, references to time and place, and descriptions of interactions with others. "They don't have the benefit of a memory record containing sensory details about something they've actually experienced," explains Geiselman.

Spontaneous Rationalizations

Though the details of the fabricated story may be sparse, deceptive people are more likely than truthful people to offer spontaneous rationalizations for the details they do provide. In other words, if they are giving you a lot of "whys" that you didn't ask for, take what they're saying with more than a grain of salt.

Unsteady as She Goes

When people are telling the truth, their words tend to flow at a consistent rate and their pitch is stable. Deceivers, Geiselman says, display dramatic fluctuations in their speech rate. They will hesitate, stammer, and use fragmented syntax. "You'll ask them a question and they'll start to answer very slowly and appear to be thinking about it, then when they decide what the answer is they speed up, almost as if they recognize that it looks like they're being deceptive by talking slowly," he says.

The Eyes Have It

Truth-tellers usually maintain eye contact with their listener. When asked a question that requires some concentration, it's natural to look away while searching for the answer — "but if it's a question that they should easily be able to answer, they shouldn't have to look away to think about it," Geiselman says. Fibbers are more likely to look at you once they've come up with their answer — to monitor your response.

Body Language

Less revealing but potentially indicative of deception are gestures and facial expressions. Those who are telling the truth are more apt to make hand gestures away from the body; liars tend to bring their hands toward their body. Other gestures warranting suspicion include grooming behaviors (fiddling with the hair, for example) and lip-biting. Watch for facial expressions that don't match what the person is saying — the furrowed brow or the inappropriate smile, for example.

Carrying a Heavy Load

Someone fabricating a story expends considerable effort to maintain his lying front. If you want to smoke him out, try doing what psychologists refer to as increasing his cognitive load. "Deceptive people have to work to maintain the lie and monitor your reactions, which truthful people don't need to do," Geiselman says. "If you can push them over the edge, these indicators of deception start to light up." Geiselman and other researchers have found, for example, that deceivers have a particularly difficult time when asked to tell their story in reverse chronological order.

Don't Try This at Home?

And just when you start to feel equipped to nab a lying spouse, child, friend or coworker, we bring you this disclaimer. With extensive training and experience, you can get pretty good at determining whether someone's account is truth or fiction. But Geiselman's research has found that a little bit of training tends to be worse than no training at all. "People will start to overanalyze the situation, and it interferes with their gut reaction," Geiselman says. "They see one indicator of deception and say, 'Aha! He's lying.' It's not that simple. These indicators are simply red flags, to give you an initial reading. But you have to dig further."



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