Catching Liars Through Cognitive Taxation

University of Portsmouth Professor, Aldert Vrij, believes we disregard all notions of specific nonverbal signals and instead look for narrative contradictions when catching liars. To that end, he provides several guidelines based on a mixture of psychological and social science exploration. Most notably, Vrij backs the proposal of “imposing cognitive load” when catching liars.

This concept of catching liars alleges that lying requires additional psychological energy to create a believable story. On the other hand, the truth does not, because the author is merely remembering, not creating. According to Vrij, a person asking questions of a subject can exploit this detail through several unique strategies. These strategies are outlined below:

1. Ask the subject for details.

The greater amount of details the subject provides, the greater chance there will be a discrepancy in what they have to say. This detail by itself may cause the guilty subject to be unwilling to answer questions or to give short or ambiguous responses. If the subject is hesitant or unclear in answering a question, the interviewer should question the subject further.

Vrij proposes borrowing from the methods of “cognitive interviewing” when catching liars, designed to improve eyewitness’ recollections, because they are valuable in encouraging the subject to report facts, they may have otherwise not remembered. Such methods consist of asking the subject to define his story with fullness and images and to assure him no aspect is without meaning or is too unimportant.

While discrepancy, ambiguity and tentativeness can be signs of dishonesty and certainly help in catching liars, details deliver the levelheadedness of more information that can be cross-referenced and confirmed.

2. Propose and encourage the subject to identify the happenings in reverse.

Because a lie is a fabrication, it may be more challenging for the deceiver to recount happenings in backwards, because such recollection manufactures extra “cognitive load.” Vrij points to studies in which subjects watched videos in which they had to differentiate a liar from someone telling the truth, this group spent some time, catching liars.

Subjects identified the liar 42% of the time when the lies where consecutive but 60% of the time when the liar had to identify the happenings in reverse.  This study proves, when catching liars, having them recount the events in reverse will have a detrimental effect on the subject cognitively

3. Ask unanticipated questions.

Vrij advocates proposing “unanticipated questions” as a counter-measure. To be effective, the interviewer must be able to cultivate pertinent questions that the subject doesn’t foresee being asked.
Vrij cites studies that confirm liars concoct less facts when responding to “surprise questions” than honest participants.

4. Perform a fact-gathering interview instead of an argumentative interview.

Vrij questions the popular Reid style of interviewing, which develops from interview to allegation. (Some examiners have declared that accomplishment-rate claims in scripts on the topic are unable to be verified or replicated.) In other words, the Reid technique assumes guilt and slowly increases pressure on the subject to confess.

In comparison, Vrij endorses the material-seeking interview, in which the interviewer attempts to establish rapport and plays an understanding role in order to lure out facts. Vrij points to a new meta-analysis of many field studies, which uncovered that fact-seeking methods produce more material and cues to dishonesty than argumentative methods.

5. Strategic Use of Evidence or in short, SUE Method

Vrij supports a method designed by Maria Hartwig in her doctoral dissertation, which studied the display of evidence in interrogations. Hartwig’s studies exhibited that the non-critical interview— asking open-ended questions and presenting evidence late in the interview—revealed more discrepancies and ambiguities than if the evidence were introduced initially.

Also, when interrogation trainees expressed indirect questions specific to the evidence without revealing their own awareness of the evidence, their ability to perceive dishonesty greatly increased.

A later study on Strategic Use of Evidence showed that trainees utilizing the Strategic Use of Evidence method produced 85% accuracy vs. 56% over a control group of interrogators not trained in Strategic Use of Evidence in defining the accuracy of statements made by subjects.