Detection of Deception in High-Stakes Liars




High-stakes lies occur where there are large positive consequences of getting away with the lie or large negative consequences of getting caught. Because the outcome of the lie is of considerable concern to the liar, it follows that he or she will probably experience more guilt and/or detection anxiety than when telling low-stakes lies. In addition, the liar will probably try particularly hard in such situations to avoid getting caught. This increased effort will be cognitively demanding, and therefore liars probably experience more cognitive load when telling high-stakes lies than when telling low-stakes lies. Accordingly, scholars believe that detecting high-stakes lies should be easier than detecting low-stakes lies. Most lies told in daily life are of the low-stakes variety; these lies are easier to replicate and hence are most commonly researched in laboratory situations. Studies of high-stakes liars have revealed, however, that their behavior is similar to that of low-stakes liars insofar as it typically reveals signs of increased cognitive load and behavioral control. Observers can make use of such signs of increased cognitive load when attempting to detect these high-stakes lies.

For practical reasons, most deception detection research has focused on low-stakes lies; a participant will be asked to lie about a fairly trivial matter for the sake of the experiment. The stakes may be raised slightly, by informing the participant either that his or her behavior will be scrutinized for sincerity by an observer or that being a good liar is an important indicator of being successful in a future career (many careers require the ability to hide one’s true feelings or intentions). Sometimes participants are motivated by the offer of a reward for a convincing performance.

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Laboratory experiments, however, cannot ethically re-create a high-stakes lie scenario. It is true that the majority of lies told by most people are low-stakes, trivial, day-to-day lies. However, what of the suspects in police interviews, smugglers at airports, speech-delivering corrupt politicians, and adulterous spouses? Some have attempted to create examples of such lies by raising the stakes further in laboratory studies—for example, by giving participants the opportunity to “steal” U.S.$50 and allowing them to keep the money if they are able to convince experimenters. Moreover, some participants have faced an additional punishment if found to be lying—for example, sitting in a cramped, dark room listening to blasts of white noise. Studies such as these raise ethical concerns and yet still fail to compete with the stakes in many real-life situations.

Another way to examine the behavior of the high-stakes liar is to look at instances where people have been caught on video telling lies and truths in real life. Such field research is more difficult than laboratory studies in that in real life it can be difficult to establish the ground truth. Therefore, it is imperative that it be known for sure when the communicator is telling the truth and when he or she is lying. In some situations, researchers have looked at suspects in their videotaped police interviews; then, through reviewing case files containing solid evidence (forensic evidence, reliable witness statements, etc.), elements of suspect interviews were established where it was known that the suspects had told the truth or lied. Treated in this fashion, similar clips can be examined for behavioral information and shown to observers to see if they are able to detect such lies.

Deception research in general has demonstrated that behavioral differences between liars and truth tellers are subtle at best and often inconsistent. They are the result of conflicting mechanisms in the liar. The liar may experience emotional arousal, which makes him or her nervous, resulting in behaviors that are stereotypically associated with lying, such as increased fidgeting, gaze avoidance, and so on. Simultaneously, the liar might try to control his or her behavior to avoid displaying such stereotypical deceptive behavior, which would result in exhibiting fewer fidgety moves and maintaining eye gaze. Finally, because lying is often (though not always) more cognitively complex than truth telling, the liar might experience behaviors associated with increased cognitive load (e.g., decreased blinking and body movements and increased pauses in speech). Laboratory research has more or less consistently revealed that, despite people’s stereotypes of lying behavior, liars are stiller than truth tellers and able to maintain eye gaze. This indicates that behavioral control and cognitive load may be more overpowering mechanisms than emotional arousal in the low-stakes liar. One would expect then that in a higher-stakes lying situation, emotions are likely to run higher. Although this might be the case, it would appear that the desire to appear credible (controlling behavior) and the cognitive load associated with telling a higher-stakes lie increase even more so, since research into the behavior of high-stakes liars such as suspects in police interviews reveals similar patterns in behavior to laboratory research subjects, with the addition of a decrease in blinking and an increase in speech pauses.

If high-stakes liars behave similarly as low-stakes liars (in that, on the whole, they display signs of increased cognitive load and increased control rather than nervousness), then could their lies be any easier to detect? As mentioned earlier, people expect certain behaviors of a liar, yet these behaviors often fail to be displayed. This is one reason why most people do not score above the level of chance when trying to detect people’s lies in experiments. In contrast, in experiments where police officers were shown clips of real-life liars and truth tellers (suspects in police interviews) and asked to make veracity judgments, the overall accuracy was more than 65%. Why it is higher is unclear. It could be that the situation that observers were being asked to judge was more contextually relevant to them than, for example, watching students who have been asked to lie or tell the truth about trivial matters. It could be that observers were able to make use of the signs of increased cognitive load that the suspects did reveal (increased pauses in speech, bodily rigidity, etc.) or perhaps that they were able to pick up on something less tangible.

References:

  1. DePaulo, B. M., Lindsay, J. L., Malone, B. E., Muhlenbruck, L., Charlton, K., & Cooper, H. (2003). Cues to deception. Psychological Bulletin, 129, 74—118.
  2. Mann, S., Vrij, A., & Bull, R. (2002). Suspects, lies and videotape: An analysis of authentic high-stakes liars. Law and Human Behavior, 26, 365-376.
  3. Mann, S., Vrij, A., & Bull, R. (2004). Detecting true lies: Police officers’ ability to detect deceit. Journal of Applied Psychology, 89, 137-149.

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