Drawing on Liars' Lack of Cognitive Flexibility: Detecting Deception Through Varying Report Modes

Abstract

The present experiment examined the role of cognitive flexibility in the consistency of truth tellers' and liars' reports. We expected liars to be less flexible (less able to report an experience in different ways) and hence less consistent than truth tellers when asked to describe an event in different ways (e.g. verbally and pictorially). In the experiment, truth tellers entered a room and performed several tasks, whereas liars did not enter the room or perform the tasks but attempted to convince an interviewer that they did. Truth tellers and liars were interviewed twice about the room and tasks, and were asked to express their answers either the same way on both interviews (e.g. verbally then again verbally) or in different ways (e.g. verbally then pictorially). In support of the cognitive flexibility hypothesis, liars' reports were less consistent than truth tellers' reports, particularly when reporting in different ways across interviews. Theoretical and practical implications are discussed.

Visuospatial counter‐interrogation strategies by liars familiar with the alibi setting

“…In a parallel manner, when liars have no experience of the reported event, they do not have a memory representation of it, so they find it difficult to include relevant spatial, sensory, and other details in their statements (Gnisci, Caso, & Vrij, 2010;Masip, Sporer, Garrido, & Herrero, 2005). This results in liars providing less detailed and consistent statements than truth-tellers who, by definition, have experienced the event (Leins, Fisher, & Vrij, 2012;Roos af Hjelmsäter et al, 2014;Vrij et al, 2009). However, if liars report about an experienced event, they would become as detailed and as forthcoming as truth-tellers Warmelink et al, 2013).…”

“…Previous studies addressed this matter by asking participants to respond to different question formats (Deeb, Vrij, Hope, Mann, Granhag, & Lancaster, 2017;Hartwig et al, 2011) or to different report modes (Leins et al, 2012;Leins, Fisher, Vrij, Leal, & Mann, 2011) across or within interviews. The manipulations proved successful in reducing liars' consistency levels more than truth-tellers' consistency levels.…”

“…Previous research has shown that varying question format across interviews has helped truth-tellers recall more information in subsequent interviews (Fisher, Brewer, & Mitchell, 2009;Granhag, Strömwall, & Jonsson, 2003), but has hindered liars from repeating information due to the difficult nature of the task (Deeb, Vrij, Hope, Mann, Granhag, & Lancaster, 2017;Leins et al, 2012). Hence, we were interested in exploring whether varying the visuospatial tasks across interviews would have an impact on statements by liars who employ counter-interrogation strategies.…”

“…We decided to allocate 30 s for the low familiarity condition, because previous studies have shown that this duration is sufficient for individuals to encode different objects within a location (e.g., Brewer & Treyens, 1981). Also, previous lie detection studies have found that a few minutes were enough for truth-tellers to familiarise themselves with the cover story setting (e.g., Leins et al, 2012;Roos af Hjelmsäter et al, 2014), so 10 min were suggested as an appropriate duration for the high familiarity condition.…”

“…Also, previous lie detection studies have found that a few minutes were enough for truth-tellers to familiarise themselves with the cover story setting (e.g., Leins et al, 2012;Roos af Hjelmsäter et al, 2014), so 10 min were suggested as an appropriate duration for the high familiarity condition.…”