Nieuwe methode van leugendetectie

Via oogbewegingen kan de computer 82,5% van de leugens detecteren

How Good a Lie Detector Are You?

The new science of spotting liars.

But now new research argues that detecting lies and deceit may actually be an unconsciousprocess. Unlike Pinocchio, most liars do not provide telltale signs that they are being dishonest. In lieu of a growing nose, is there a way to distinguish people who are telling the truth from those who aren’t? In a study published in Psychological Science in the Public Interest, Aldert Vrij of the University of Portsmouth, Anders Granhag of the University of Gothenburg, and Stephen Porter of the University of British Columbia suggest verbal methods of deceptiondetection are more useful than nonverbal methods commonly believed to be effective, and that there are psychological differences between liars and truth-tellers that can be exploited in the search for the truth.

Trapping a liar is not always easy, the authors argue. Lies are often embedded in truths and the behavioral differences between liars and truth-tellers are usually very small. In addition, some people are just very good at lying. Lie detectors routinely make the common mistakes of overemphasizing nonverbal cues, neglecting intrapersonal variations (i.e., how a person acts when they are telling the truth versus when they are lying), and being overly confident in their lie-detection skills.

This research has important implications in a variety of settings, the authors write, including the courtroom, police interviews, and screening and identifying individuals with criminal intent—such as potential terrorists.

Leanne ten Brinke and her colleagues at the University of California, Berkley’s Haas School of Business have published a study in Psychological Science, in which they conclude 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 may not be all that indicative of an untrustworthy person.

“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 if participants simply guessed whether a person was lying. And it’s a finding that seems at odds with the fact that humans are typically quite sensitive to how others are feeling, what they’re thinking, and what their personalities are like.

The authors concluded that seemingly paradoxical findings may be accounted for by unconscious processes: “We set out to test whether the unconscious mind could catch a liar—even when the conscious mind failed,” she says.

The results of their study showed that participants were more likely to unconsciously associate deception-related words (untruthful, dishonest, deceitful) with suspects who were actually lying. At the same time, participants were more likely to associate truthful words (honest, valid) with suspects who were actually telling the truth. A second experiment confirmed these findings, providing evidence that people may indeed have some intuitive sense, outside of our conscious awareness, that detects when someone is lying.

“These results provide a new lens through which to examine social perception, and suggest that—at least in terms of detection of lies—unconscious measures may provide additional insight into interpersonal accuracy,” according to ten Brinke.

Another study, conducted by ten Brinke and Stephen Porter of the University of British Columbia, analyzed films of liars and truth tellers from high-profile press conferences in which people appealed for missing relatives or claimed to have been the victims of crimes. “Our previous research with these films suggests that there are significant differences in the behavior of liars and truth tellers,” ten Brinke noted. “However, the alleged telltale pattern of eye movements failed to emerge.” Lie Detectors 2.0

Has technology advanced sufficiently to assist in the detection of lies? Yes, according to astudy by Ifeoma Nwogu, a research assistant professor at the University of Buffalo’s Center for Unified Biometrics and Sensors (CUBS); colleagues Nisha Bhaskaran and Venu Govindaraju; and University of Buffalo communications professor Mark G. Frank, who presented their findings at the 2011 IEEE Conference on Automatic Face and Gesture Recognition.

In their study of 40 videotaped conversations, an automated system analyzing eye movements correctly identified whether subjects were lying or telling the truth 82.5 percent of the time. That’s a better accuracy rate than expert human interrogators typically achieve in lie-detection judgment experiments. (Experienced interrogators average closer to 65 percent.)

“What we wanted to understand,” Nwogu said, “was whether there are signal changes emitted by people when they are lying, and can machines detect them?”

In the past, attempts to automate deceit detection have used systems that analyze changes in body heat or examine a slew of involuntary facial expressions. The automated system used by Nwogu’s team tracked a different trait—eye movement—and employed a statistical technique to model how people moved their eyes in two distinct situations: during regular conversation, and while fielding a question designed to prompt a lie.

People whose pattern of eye movements changed between the first and second scenario were assumed to be lying, while those who maintained consistent eye movement were assumed to be telling the truth. In other words, when the critical question was asked, a strong deviation from normal eye movement patterns suggested a lie. Previous experiments in which human judges coded facial movements found documentable differences in eye contact at times when subjects told a high-stakes lie.

Liars Can’t Foll All the People, All the Time

Researchers studying the faces of people lying when in high-stakes situations have good news for security experts: Another recent study found that although liars can reduce telltale facial actions when under scrutiny, they can’t suppress them all, and microexpressions in the face may indicate a person is being deceptive. The study by Mark Frank and Carolyn Hurley, which was published in the Journal of Nonverbal Behavior, examined whether subjects could suppress facial actions like eyebrow movements or smiles on command while under scrutiny by a lie catcher. It turns out that the subjects could, to a degree, but not completely and not always.

The results were derived from frame-by-frame coding of facial movements filmed during interrogations in which participants—some lying and some telling the truth—were asked to suppress specific parts of facial expressions. Hurley and Frank found that these actions could be reduced, but not eliminated, and that instructions to subjects to suppress one element of expression resulted in reduction of all facial movement, regardless of their implications for veracity. “Behavioral countermeasures,” according to Frank, “are the strategies engaged by liars to deliberately control face or body behavior to fool lie catchers.” Until this study, research had not shown whether or not liars could suppress elements of their facial expression as a countermeasure. “As a security strategy,” he says, “there is great significance in observing and interpreting nonverbal behavior during an investigative interview, especially when the interviewee is trying to suppress certain expressions.

“Although these facial movements are not necessarily guaranteed signs of deception,” says Frank, “expression suppression—regardless of its validity as a clue to deception—is clearly one of the more popular strategies used by liars to fool others. What we didn’t know was how well individuals can do this when they are lying or when they are telling the truth.

“We correctly predicted that in interrogations in which deception is a possibility, individuals would be able to significantly reduce their rate and intensity of smiling and brow movements when requested to do so, but would be able to do so to a lesser degree when telling a lie. And since the lower face (and smile in particular) is easier to control than the upper face, we predicted that our subjects would more greatly reduce their rate of smiling, compared to their rate of brow movement, when requested to suppress these actions,” he says. “That turned out to be the case as well. We can reduce facial movements when trying to suppress them but we can’t eliminate them completely.”

Who Are the Best Lie Detectors?

Are certain kinds of people or personality types better at spotting lies? That’s a question that Nancy Carter and Mark Weber of the Rotman School of Management at the University of Toronto asked in their study, published in Social Psychological and Personality Science.Trusting others may not make you a sucker, they found; it might actually be a sign of yourintelligence.

The researchers found that people high in trust were more accurate at detecting the liars—the more people showed trust in others, the more able they were to distinguish a lie from the truth. The more faith in their fellow humans they had, the more they wanted to hire the most honest interviewees and avoid liars. Contrary to the stereotype, people low in trust were more willing to hire liars—and less likely to be aware that those people were liars.

“Although people seem to believe that low trusters are better lie detectors and less gullible than high trusters, these results suggest that the reverse is true,” Carter and Weber wrote. “High trusters were better lie detectors than were low trusters; they also formed more appropriate impressions and hiring intentions. People who trust others are not pie-in-the-sky Pollyannas; their interpersonal accuracy may make them particularly good at hiring, recruitment, and identifying good friends and worthy business partners.”

Key linguistic cues can help reveal dishonesty as well, whether it’s a deliberate omission of information, or a complete lie, according to research by Lyn M. Van Swol, Michael T. Braun of the University of Wisconsin and Deepak Malhotra of Harvard University, published in the journal Discourse Processes.

“Most people admit to having lied in negotiations, and everyone believes they’ve been lied to in these contexts,” Malhotra says. “We may be able to improve the situation if we can equip people to detect and deter the unethical behavior of others.”

Previous studies examined the linguistic differences between lies and truthful statements. But this one went a step further, considering the differences between flat-out lies and deception by omission—the willful avoidance of divulging important information, either by changing the subject or saying as little as possible.

The researchers recruited 104 participants to play “the ultimatum game,” a popular tool among experimental economists. They discovered that liars tended to use many more words than truth tellers, presumably in an attempt to win over suspicious receivers. The researchers called this “the Pinocchio effect.” In contrast, individuals who engaged in deception by omission used fewer words and shorter sentences than truth tellers. Liars used more swear words than truth tellers, and more third-person pronouns than truth tellers or omitters. Finally, liars spoke in more complex sentences than truth tellers. We are increasingly facing issues of lying and deception with respect to political leaders and business leaders. It will be interesting to see if this research affords us better tools to deal with the problem.