This is the fourth installment adapted from an earlier paper in conjunction with an ABA Section of Litigation Annual Meeting presentation. I’m sharing this knowledge with WLALA over several months.
Clues to Deceit. Deception clues can be discovered in the length of answers to interrogations or questions. In rehearsed situations, answers get longer. If unrehearsed, we find the opposite. Liars are not always vivid with details. Innocent witnesses often tell the story with irrelevant material. They add details that aren’t useful to the core of what occurred, but are included as the person tells the story. Liars prepare in a linear direction (e.g., this happened, next this, then . . .).
Affect is a big clue especially when it differs from the person’s baseline of expressions. If the witness is generally animated and the voice suddenly flattens, look at the specific content of the testimony. When affect changes, there are fewer illustrator movements with hands, the head, and the upper eyelids. There are many kinds of smiles. We all have encountered fake smiles. There is a big difference between polite smiles and enjoyment smiles. Guilt cues are not as clearly determined, but could include cues to sadness such as lower pitch, softer and slower speech, and downward gazing.
When liars deceive, they become psychologically aroused in a way that puts stress on the voice, leading to an increase in pitch. In Ekman and Friesen’s study using nursing students as the stimuli – one group telling lies and the other group is telling the truth. They measured the nursing students’ pitch through a speech analysis computer program. This analysis indicated that those in the lying condition had significant increases in pitch.[ii]
Gestural slips are changes in behavior that occur when some emotion is felt. There may be a shoulder shrug, covering the mouth or body shift. Nonverbal behavior is not as easily edited as verbal behavior. Examples include the voice going higher or a pained expression on the witness’ face.
DePaulo’s monumental meta-analyses of the empirical studies on deception report 158 cues to deception.[iii] Results show that liars make a negative impression and are more tense. Many behaviors have weak or no discernable links to deceit. Cues to deception are more pronounced when people are motivated to succeed, especially when dealing with identity challenges rather than money gains. Cues to deception are stronger when lies are about transgressions.
Besides detecting deception through emotions and micro expressions, there are a number of other methods. Besides the widely known method of polygraphs, thermal imaging uses a physiological method recording skin temperature.[iv] Another method to outsmart liars, uses questions about spatial and/or temporal information. Vrij et al. found that up to 80% of liars and truth tellers could be correctly identified when assessing their drawings.[v]
Interview style makes a difference in ability to detect lies. Accusatory styles typically result in suspects making short denials, thus fewer verbal cues that might reveal deceit.[vi] There is a higher probability of making false accusations than when using an open-ended information gathering strategy. Liars interviewed by trained interviewers were more inconsistent leading to the trained interviewers’ greater accuracy rate in detecting deception.[vii]
Clues to Spotting Lying
§ Affect differs from baseline
§ Smiles inconsistent with emotion
§ Micro expressions revealing inappropriate emotions
§ Signs of fear or guilt
§ Fear cues (higher pitch, faster/louder speech, speech errors, indirect speech)
§ Gestural slips (e.g., shoulder shrugs)
§ Shifting eyes if linked to other signs
§ Length of answers, details
§ Can’t tell the story backward
Next month’s column will discuss credibility in witnesses.
Ekman, P.E. (1985). Telling Lies: Clues to Deceit in the Marketplace, Politics, and Marriage, New York, W.W. Norton & Company.
[ii] Ekman, P.E., & Friesen, W.V. (1969). Nonverbal leakage and clues to deception. Psychiatry, 32, 88-106.
[ii] DePaulo, B.M., Malone, B.E., Lindsay, J.J., Muhlenbruck, L. Charlton, K., & Cooer, H. (2003). Cues to deception. Psychological Bulletin, 129 (1), 74-118.
[iv] Warmelink, L., Vrij, A., Mann, S., Leal, S., Forrester, D. & Fisher R.P. (2011). Thermal imaging as a lie detection tool at airports. Law and Human Behavior, 35 (1), 40-48.
[v] Vrij, A., Leal, S., Granhag, P.A., Mann, S., Fisher, R.P., Hillman, J., & Sperry, K. (2009). Outsmarting the liars: The benefit of asking unanticipated questions. Law and Human Behavior, 33 (2), 159-166.
[vi] Vrij, A., Mann, S., Kristen, S., & Fisher, R. P. (2007). Cues to deception and ability to detect lies as a function of police interview styles. Law and Human Behavior, 31(5), 499-518.
[vii] Hartwig, M., Granhag, P.A., Stomwall, L.A., & Kronkvist, O. (2006). Law and Human Behavior, 30 (5), 603-619.