Repeated interrogations: verbal and non‐verbal cues to deception

Abstract

The major aim of this study was to investigate to what extent verbal and non-verbal features of liars' and truth-tellers' behaviour change during the course of repeated interrogations. After seeing a staged event, 24 suspects (12 liars and 12 truth-tellers) were interrogated three times over a period of 11 days. In terms of the non-verbal features, and in line with our prediction, we found that the liars displayed significantly fewer smiles, self-manipulations, pauses, and less gaze aversion than truthtellers. Furthermore, over time the initial differences between liars' and truth-tellers' non-verbal behaviour increased for smiles, gaze aversion and pauses. In addition, we found that the cue 'richness of detail'-the most indicative verbal marker for truth as given in previous research-had no discriminative power at any of the interrogation sessions. Finally, and in contrast to beliefs held by supposed expert lie-catchers (e.g. judges and police officers), truthful and deceptive statements were found to be equally consistent over time. The psycho-legal implications of the above findings are discussed.In real-life psycho-legal contexts there is a high likelihood that a suspect will be interrogated on numerous occasions (see e.g. Miller and Stiff, 1993). Research on deception has to a large extent neglected this fact and, instead, focused heavily on situations where each suspect is questioned about a particular event just once. This leaves unresolved the question of how suspects' verbal and non-verbal behaviour is affected by repeated interrogations. The current study's major aim is to investigate the extent to which the verbal and non-verbal features of liars' and truth-tellers' behaviour change during repeated interrogations. Differently put, the study asks whether the behaviour displayed by liars and truth-tellers becomes more or less similar over time. REPEATED INTERROGATIONS FROM THE SUSPECT'S PERSPECTIVE Non-verbal behaviourIn an attempt to establish a theoretical framework for deceptive non-verbal behaviour, it has been suggested that certain types of internal processes translate into certain types of nonverbal behaviour which, in turn, is indicative of deception (Vrij, 1998;DePaulo et al., 1985). Three different approaches to non-verbal deceptive behaviour have been defined:

Getting into the Minds of Pairs of Liars and Truth Tellers: An Examination of Their Strategies

“…Given the importance, it is surprising that truth tellers' and liars' strategies to appear credible in an interview have been understudied for a long time (DePaulo, Lindsay, Malone, Muhlenbruck, Charlton, & Cooper, 2003). However, DePaulo et al's (2003) plea for research into this area has resulted in several studies (Colwell, Hiscock-Anisman, Memon, Woods, & Michlik, 2006;Granhag & Strömwall, 2002;Strömwall, Granhag, & Landström, 2007;Strömwall, Hartwig, & Granhag, 2006). …”

The Effect of Cognitive Load on Deception

“…Particularly relevant to arousal-based interview protocols is the belief that liars exhibit increased gaze aversion and body movements. Research has not only failed to support these beliefs, but there is evidence of the opposite effect (Granhag & Stromwall, 2002). These reviews of the deception detection literature confirm that the current arousal-based methods utilized by the law enforcement community may not be the most effective means by which to identify deceit (DePaulo et al, 2003;Vrij, 2008;Vrij, Mann, & Fisher, 2006a).…”

“…In numerous studies, participants have reported that telling a lie is more cognitive demanding than telling the truth (Granhag & Stromwall, 2002;Stromwall, Hartwig, & Granhag, 2006;Vrij, Edward & Bull;2001;Vrij et al, 2006b;Vrij et al, 1996). These reports support the notion that lying requires more cognitive resources than truth-telling and that individuals are aware of increased cognitive demands that accompany deception.…”

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

“…Preparation enables liars to avoid the need to improvise spontaneous lies (Vrij, Granhag, Mann, & Leal, 2011) and to stick to their cover story during the interview and hence provide a consistent statement (Granhag & Strömwall, 2002;Vrij et al, 2009). …”

“…Their primary focus is to provide detailed and consistent statements rather than statements similar to those of truth-tellers (Deeb, Vrij, Hope, Mann, Granhag, & Lancaster, 2017;Harvey, Vrij, Leal, Hope, & Mann, 2017;Sakrisvold, Granhag, & Mac Giolla, 2017;Strömwall & Willén, 2011). Although they are able to provide statements that resemble those of truth-tellers if they are equally familiar with the reported event (Blandón-Gitlin et al, 2005;Warmelink et al, 2013), their concern about being detailed and consistent may make them more detailed and consistent than truth-tellers when they employ counter-interrogation strategies (Deeb, Vrij, Hope, Mann, Granhag, & Lancaster, 2017;Granhag & Strömwall, 2002;Harvey, Vrij, Leal, Hope, et al, 2017). In other words, liars who are familiar with the reported event or interview technique may not necessarily provide statements similar to those of truth-tellers.…”