[Paleopsych] Science News: Deception Detection

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Deception Detection: Science News Online, July 31, 2004
http://www.sciencenews.org/articles/20040731/bob8.asp

Psychologists try to learn how to spot a liar

    Carrie Lock

    "Is he lying?" Odds are, you'll never know. Although people have been
    communicating with one another for tens of thousands of years, more
    than 3 decades of psychological research have found that most
    individuals are abysmally poor lie detectors. In the only worldwide
    study of its kind, scientists asked more than 2,000 people from nearly
    60 countries, "How can you tell when people are lying?" From Botswana
    to Belgium, the number-one answer was the same: Liars avert their
    gaze.

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                                                              Dean MacAdam

    "This is . . . the most prevalent stereotype about deception in the
    world," says Charles Bond of Texas Christian University in Fort Worth,
    who led the research project. And yet gaze aversion, like other
    commonly held stereotypes about liars, isn't correlated with lying at
    all, studies have shown. Liars don't shift around or touch their noses
    or clear their throats any more than truth tellers do.

    For decades, psychologists have done laboratory experiments in an
    attempt to describe differences between the behavior of liars and of
    people telling the truth. Some researchers, however, are now moving
    away from those controlled conditions and are inching closer to
    understanding liars in the real world. The researchers are examining
    whether several behaviors that have emerged as deception signals in
    lab tests are associated with real-life, high-stake lies. The
    psychologists are also testing how well professional sleuths, such as
    police and judges, can detect deceptions.

    One thing, however, is certain: There is no unique telltale signal for
    a fib. Pinocchio's nose just doesn't exist, and that makes liars
    difficult to spot.

    Lab lies

    By studying large groups of participants, researchers have identified
    certain general behaviors that liars are more likely to exhibit than
    are people telling the truth. Fibbers tend to move their arms, hands,
    and fingers less and blink less than people telling the truth do, and
    liars' voices can become more tense or high-pitched. The extra effort
    needed to remember what they've already said and to keep their stories
    consistent may cause liars to restrain their movements and fill their
    speech with pauses. People shading the truth tend to make fewer speech
    errors than truth tellers do, and they rarely backtrack to fill in
    forgotten or incorrect details.

    "Their stories are too good to be true," says Bella DePaulo of the
    University of California, Santa Barbara, who has written several
    reviews of the field of deception research.

    Liars may also feel fear and guilt or delight at fooling people. Such
    emotions can trigger a change in facial expression so brief that most
    observers never notice. Paul Ekman, a retired psychologist from the
    University of California, San Francisco, terms these split-second
    phenomena "microexpressions." He says these emotional clues are as
    important as gestures, voice, and speech patterns in uncovering
    deceitfulness.

    But not all liars display these signals, and one can't conclude people
    are lying because they don't move their arms or pause while telling
    their stories. These could be natural behaviors for them, not signs of
    lying. "They are statistically reliable indicators of deception," says
    Timothy Levine of Michigan State University in East Lansing, but that
    doesn't mean they're helpful in one-on-one encounters.

    People don't seem to be very good at spotting deception signals. On
    average, over hundreds of laboratory studies, participants distinguish
    correctly between truths and lies only about 55 percent of the time.
    This success rate holds for groups as diverse as students and police
    officers. "Human accuracy is really just barely better than chance,"
    says DePaulo.

    Some researchers think, however, that the design of the laboratory
    studies is responsible for the poor rates of lie detection. "People
    are very good liars when nothing is at stake," says Aldert Vrij of the
    University of Portsmouth in England. "But a lab setting is not real
    life."

    In most experiments, researchers tell the subjects whether or not to
    lie, and the lies have no effect on their lives. There's no
    significant reward for a liar who's believed or punishment for a judge
    who's duped.

    "There is definitely a lack of real-life stuff in this field of
    research," says Vrij.

    True liars

    Vrij has been looking at lies told not by participants in an
    experiment but by actual suspects in police-interrogation rooms. A
    major difficulty in using real-life lies is that the researchers
    themselves often don't know the truth. To overcome that obstacle, Vrij
    obtained police-recorded videotapes in which 16 suspects in the United
    Kingdom, charged with offenses such as arson and murder, told both
    lies and truths about their alleged involvement in the crimes. The
    police used forensic evidence, witness accounts, and the suspects'
    eventual confessions to determine the actual events.

    Before learning the police conclusions, Vrij's team analyzed the
    videotapes for signs of the suspects' nonverbal reactions to
    questioning, such as gaze aversion, blinking, and hand-and-arm
    movements. They also looked at verbal cues, such as pauses in speech
    and speech disturbances, including "ahs," stutters, and incomplete
    sentences.

    The differences between lying and truth telling were largely
    individual: Some suspects looked away more while lying than while
    telling the truth, and others increased their degree of eye contact,
    for example. The only general difference Vrij found between liars and
    truth tellers is that the liars blinked less frequently and paused
    longer while speaking.

    In contrast to participants in the lab studies, the crime suspects
    didn't show any overall increase in speech disturbances or decrease in
    hand-and-arm movements. Because of the intense nature of a police
    interrogation, stressed truth tellers may display the same behaviors
    as liars do, Vrij speculates.

    He is currently exploring lie detection from the side of the
    interviewer rather than the suspect. He showed 99 police officers
    tapes of real-life lies and truths and found that the officers were,
    at 65 percent accuracy, slightly better than lab-study participants at
    discerning the difference. But police are "still far away from
    perfect," Vrij points out.

    He attributes the police officers' slightly better performance
    primarily to the nature of the lies they hear during an interrogation.
    "More is at stake, and that gives the lies away more," he says.

    Most recently, Vrij has tested whether the police officers' accuracy
    rates are consistent in multiple tests. In this study, 35 police
    officers took four tests derived from interviews of either liars or
    truth tellers, and 70 percent of the professionals' calls were
    correct.

    Although the officers again outperformed participants in lab studies,
    no individual officer stood out. "Our early findings indicate that
    none was consistently good or consistently bad," Vrij says. "Nobody is
    80 percent overall."

    Wizards of detection

    Other researchers, however, present evidence that highly skilled human
    lie detectors do exist. The scientists have been trying to identify
    such people and figure out how they recognize lies.

    In a now-famous study from more than a decade ago, about 500 Secret
    Service agents, federal polygraphers, and judges watched 10 1-minute
    video clips of female nurses describing the pleasant nature films they
    were supposedly watching as they spoke. Half the women were instead
    watching what Ekman calls "terribly gruesome" medical films. The
    legal-system professionals were asked to determine the truth by
    reading the women's faces, speech, and voices.

    Ekman and his coauthor Maureen O'Sullivan of the University of San
    Francisco motivated the women to lie by telling them that because
    nurses shouldn't be bothered by gory images, their believability
    related to their future career success.

    Most of the observers uncovered lies at only about the level of
    chance. One group, however, outperformed the others. The Secret
    Service group had a better-than-chance distribution, with nearly
    one-third of the agents getting 8 out of 10 determinations correct,
    the San Francisco psychologists reported in 1991.

    O'Sullivan now says that her further studies of federal agents,
    forensic psychologists, and other groups of professionals indicate
    that a very small percentage of people are extremely good at spotting
    a phony. "We always found one or two people who were very good," she
    says.

    Over the past decade, she has given a series of tests to more than
    13,000 people from all walks of life, including therapists, police
    officers, law students, artists, and dispute mediators. In the first
    test, college students either lie or tell the truth about a strongly
    held opinion, such as their views on abortion or the death penalty.
    The researchers motivate the students by instituting a system of
    rewards and punishments, although for ethical reasons, the study
    participants know that they can withdraw at any time.

    The subjects are told that if they are judged to be lying, even if
    they're not, they'll be locked in a dark room about the size of a
    telephone booth for 2 hours and subjected to intermittent blasts of
    noise. "We actually didn't do that, but that was the threat," says
    O'Sullivan.

    If a student is believed, he or she earns $50 to $100. These rewards
    and punishments, Ekman says, "cross a certain threshold so that you
    generate similar behavior and emotional clues" in the experiment and
    in real life.

    Observers who judge the students' opinions correctly 90 percent of the
    time or better move on to two more tests. The motivation for the
    students to lie remains the same.

    In the first of these tests, students describe their participation in
    a mock crime scenario. The second test again uses nurses lying or not
    lying about watching nature films. Human lie detectors who get 80
    percent correct on both the additional tests are "ultimate wizards" of
    lie detection, says O'Sullivan.

    She has identified only 15 people as ultimate wizards, about 0.1
    percent of the people who have taken the series of tests. "People who
    are extraordinarily good are extraordinarily good, no matter what the
    lie is," says Ekman. Another 16 people are "penultimate wizards,"
    getting 80 percent on either the mock-crime test or the nature-film
    test, but not on both.

    O'Sullivan has asked the wizards questions about their lie-detection
    processes. "All of them pay attention to nonverbal cues and the
    nuances of word usages and apply them differently to different
    people," she says. "They could tell you eight things about someone
    after watching a 2-second tape. It's scary, the things these people
    notice," she says.

    O'Sullivan compares these skillful observers to Agatha Christie's
    fictional Miss Marple, who could instantly judge the veracity of
    someone by comparing him or her to people she'd already encountered.

    Bond, however, doubts that O'Sullivan's experiments can be
    successfully applied to real-life liars. The system of rewards and
    punishment doesn't make the laboratory environment similar to a
    police-interrogation room. "A dark room and noise is not comparable to
    the threat of lethal injection," Bond says.

    He also suggests that the supposed lie-detection wizards are just
    people who happen by chance to do well on all three of O'Sullivan's
    tests. O'Sullivan, however says that's unlikely.

    Bond and DePaulo recently reviewed 217 studies going back 60 years
    that together include tens of thousands of subjects. The analysis
    found no evidence of significant differences between people in their
    ability to detect lies in various scenarios, Bond says.

    Ekman and O'Sullivan speculate that if they could only study enough
    people, they might learn specific techniques that good lie detectors
    use. Then, it might be possible to deconstruct their skill and teach
    it to others, such as police officers, the researchers say.

    Vrij, for instance, reports in the April Applied Cognitive Psychology
    that he has increased people's accuracy by a few percent by teaching
    them to make quick assessments of behaviors such as the frequency of
    hand movements. However, Levine speculates that even a bogus program
    can succeed by simply getting people to pay attention.

    "Training may increase your hit rate a little bit in the long run, but
    you're still missing a lot," Levine says.

    But because witnesses, hard facts, and physical evidence are often
    scarce, Ekman says, "it's worth training people to be as accurate as
    they can be."

    References:

    Bond, C., et al. A world of deception. (unpublished
    manuscript--submitted to Journal of Cross-Cultural Psychology, but not
    yet accepted.)

    Ekman, P., and M. O'Sullivan. 1991. Who can catch a liar? American
    Psychologist 46(September):913-920. Available at
    [25]http://www.paulekman.com/pdfs/who_can_catch_a_liar.pdf.

    Mann, S., A. Vrij, and R. Bull. 2004. Detecting true lies: Police
    officers' ability to detect suspects' lies. Journal of Applied
    Psychology 89(February):137-149. [26]Abstract.

    Mann, S., A. Vrij, and R. Bull. 2002. Suspects, lies, and videotape:
    An analysis of authentic high-stake liars. Law and Human Behavior
    26(June):365-376. Abstract available at
    [27]http://dx.doi.org/10.1023/A:1015332606792.

    Park, H.S., T.R. Levine, et al. 2002. How people really detect lies.
    Communication Monographs 69(June):144.

    Vrij, A. In press. Why professionals fail to catch liars and how they
    can improve. Legal and Criminological Psychology.

    Vrij, A., et al. 2004. Rapid Judgments in assessing verbal and
    nonverbal cues: Their potential for deception researchers and lie
    detection. Applied Cognitive Psychology 18(April):283-296. Abstract
    available at
    [28]http://www3.interscience.wiley.com/cgi-bin/abstract/107639963/ABST
    RACT.

    Further Readings:

    DePaulo, B.M., and W.L. Morris. In press. Discerning lies from truths:
    Behavioral cues to deception and the indirect pathway of intuition. In
    Deception Detection in Forensic Contexts, Granhag, P.A., and L.
    Stromwall, eds. Cambridge: Cambridge University Press.

    Ekman, P. 1997. Lying and deception. In Memory for Everyday and
    Emotional Events, Stein, N.L., P.A. Ornstein, B. Tversky, and C.
    Brainerd, eds. Mahway, New Jersey: Lawrence Erlbaum Associates.
    Available at
    [29]http://www.paulekman.com/pdfs/lying_and_deception.pdf.

    Ekman, P. 1996. Why don't we catch liars? Social Research
    63(Fall):801-807. Available at
    [30]http://www.paulekman.com/pdfs/why_do_not_we_catch_liars.pdf.

    Frank, M.G., and P. Ekman. 1997. The ability to detect deceit
    generalizes across different types of high-stake lies. Journal of
    Personality and Social Psychology 72(June):1429-1439. Available at
    [31]http://www.paulekman.com/pdfs/ability_to_detect_deceit.pdf.

    Levine, T.R., and S.A. McCornack. 2001. Behavioral adaptation,
    confidence, and heuristic-based explanations of the probing effect.
    Human Communication Research 27(October):471-502. Abstract available
    at [32]http://hcr.oupjournals.org/cgi/content/abstract/27/4/471.

    Levine, T.R., et al. 2000. Norms, expectations, and deception: A norm
    violation model of veracity judgment. Communication Monographs
    67(June):123-137.

    Levine, T.R., H.S. Park, and S.A. McCornack. 1999. Accuracy in
    detecting truths and lies: Documenting the "veracity effect."
    Communication Monographs 66(June):125.

    Vrij, A. In press. Guidelines to catch a liar. In Deception Detection
    in Forensic Contexts, Granhag, P.A., and L. Stromwall, eds. Cambridge:
    Cambridge University Press.

    Sources:

    Charles Bond
    Department of Psychology
    Texas Christian University
    TCU Box 298920
    Fort Worth, TX 76129

    Bella M. DePaulo
    Department of Psychology
    University of California, Santa Barbara
    Santa Barbara, CA 93106

    Paul Ekman
    P.O. Box 5211
    Berkeley, CA 94705

    Mark Frank
    Department of Communication
    Rutgers University
    4 Huntington Street
    New Brunswick, NJ 08901

    Timothy Levine
    Department of Communication
    Michigan State University
    482 Comm Arts Building
    East Lansing, MI 48824

    Maureen O'Sullivan
    Department of Psychology
    University of San Francisco
    2130 Fulton Street
    San Francisco, CA 94117

    Aldert Vrij
    Department of Psychology
    University of Portsmouth
    King Henry Building
    King Henry I Street
    Portsmouth PO1 2DY
    United Kingdom