Using Linguistics as a Lie Detector

Using Linguistics as a Lie Detector

Learning to listen for distinct speaking patterns and cues can help internal auditors become more effective during their investigations and interviews.

Nejolla Korris
InterVeritas International

People — not just fraud investigators or law enforcement — are inherently fascinated by the ability to detect lies. Books written on the subject describe one tip after another about how to spot a liar, while others break down and dissect the human psyche. According to Pamela Meyer, author of Liespotting, a person could be lied to as many as 200 times a day.

While lying may be a part of everyday life, not all lies have malicious intent. Lies may be told to save face, to preserve the peace, or to protect someone’s feelings. However, malicious lies — those intended to mislead or cover up — are the ones audit and fraud professionals are most confronted with during their investigations.

Internal auditors who haven’t received extensive interrogation or interviewing training can still become effective investigators through a linguistic lie detection technique known as Scientific Content Analysis (SCAN). SCAN — a process of analyzing oral and written testimonies — was introduced by Avinoam Sapir in the 1980s after he oversaw the Israeli Police’s polygraph department. Sapir observed that distinct speaking patterns exist in truthful responses, while different patterns emerge with deceptive responses. Although internal auditors may not need to investigate deception during every audit engagement, using the SCAN methodology can help them become better investigators and observers of responses to their questions.


Too many times, investigators attempt to solve a case by making assumptions about what they think happened and then formulating questions based on those assumptions. Often, the suspect realizes the investigator does not really know what happened and merely answers questions in a way that deflects personal responsibility. To avoid this kind of response, investigators first need to obtain a statement from the suspect and then build the investigative component (i.e., the interview). At this point, it is important for the investigator to refrain from asking specific questions about the incident.

One way to gain a comprehensive statement is to ask the suspect to describe what happened from the time he or she woke up until the time he or she went to sleep. Doing so allows the investigator to remain in control of the interview and avoid revealing what he or she knows — and does not know — about the case. Obtaining a first-hand rundown of the suspect’s entire day also may provide insight about why he or she committed the crime. For example, an early-morning fight with her husband over medical bills may have been the precipitating factor that caused a soft count supervisor to steal thousands of dollars by manipulating the day’s count and wrap. The supervisor may have been contemplating the fraud for a while, but the fight with her husband likely was the trigger.


Once the investigator has the suspect’s account of the event, he or she can use the SCAN process to look for linguistic markers when analyzing the statement. Specific markers and triggers can illustrate the suspect’s commitment to his or her story and indicate where deception may be present.

  • Pronouns. Omission of first-person pronouns (e.g., “I” or “we”) can indicate deception and also suggest the subject does not want to be attached to the narrative. A suspect who is being dishonest often will substitute a personal pronoun for the name of a relative when discussing a family member or close friend. For example, when spouses talk about each other, they normally use their partner’s name. When they are lying, however, they may avoid calling the spouse by name and instead use pronouns, even where pronouns sound unnatural.
  • Verb tense. Most truthful statements are written or spoken in the past tense. Switching from past to present tense when describing the event may indicate the suspect is making up the story as he or she is going along.
  • Structure. If the setting of the scene leading up to the action or crime takes up an inordinately large portion of the statement, it may be coming from a suspect's imagination rather than from his or her memory. Eighty-five percent of deceivers spend an overwhelming majority of time talking about the time before the crime rather than the crime itself, according to research conducted by the Laboratory for Scientific Interrogation.

After analyzing the statement, the investigator should have the necessary information to prepare for the interview. All investigators should include two questions in their interviewing repertoire.

  • Is there anything else you want to tell me?
  • Is there anything else you think I should know?

These are two very different questions. One indicates a voluntary response, while the other indicates an obligatory response.


Interviewing is a fascinating and important part of any investigation. With each interview an internal auditor conducts, he or she will begin to realize that there are no mistakes in language. The key is learning to listen to what people are really saying. True feelings and intent are often cloaked by words in an attempt to hide the real meaning.

Nejolla Korris is CEO of InterVeritas International in Edmonton, Canada, and has more than 20 years of international business experience — 11 of which have been focused on detecting deception. Korris is skilled in the SCAN technique and has analyzed documents for fraud, arson, assault, homicide, and missing persons’ cases.