The devil is in the detail: deception and consistency over repeated interviews

Abstract

Word count: 200Research indicates that truthful statements typically contain more details than fabricated statements, and that truth tellers are no more consistent than liars over multiple interviews. In this experiment, we examine the impact of (i) multiple interviewers and (ii) reverse order recall on liars' and truth tellers' consistency and amount of reported detail over repeated recall attempts. Participants either took part in a mock crime (lying condition) or an innocent event (truth telling condition) which they were subsequently interviewed about in two separate interview phases. Truth tellers provided more details overall, and more reminiscent details than liars. There were no differences between veracity groups for the number of omissions made or repetitions reported. Despite the popular belief that inconsistency is a cue to deception, we found little support for the notion that consistency (or lack of consistency) offers a diagnostic cue to deception. We found little evidence that switching interviewer or recalling in reverse order induced inconsistencies in liars. In fact, due to the number of reminiscent details in truth tellers' accounts, our findings suggest that accounts provided by liars tend to be slightly more consistent than those provided by truth tellers. The materials for this paper can be found at osf.io/hgvmk/. Keywords (5): consistency, detecting deception, investigative interviewing, lying, reverse order recall DECEPTION AND CONSISTENCY OVER REPEATED INTERVIEWS 3The devil is in the detail: Deception and consistency over repeated interviews.Research has consistently shown that people are relatively poor at recognising when someone is lying (Hartwig et al., 2011; ten Brinke, Vohs, & Carney, 2016). Meta-analyses reveal that humans' ability to detect deception rarely exceeds chance (Bond & DePaulo, 2006), and that there is little difference in accuracy between laypeople and practitioners who work in fields where attempts to deceive are commonplace (Aamodt & Custer 2006;Bond & DePaulo, 2006). Even when investigators are trained to look for cues to deception, only a small to medium training effect for accuracy in distinguishing between truth tellers and liars is found with the largest effect sizes found for training that focuses on verbal content (Hauch, Sporer, Michael, & Meissner, 2016). Given people's poor ability to differentiate between truth tellers and liars, researchers have been working towards developing interviewing techniques designed to increase the differences in verbal cues between truth tellers and liars (e.g. Strategic Use of Evidence,

Eliciting information and cues to deception using a model statement: Examining the effect of presentation modality

“…Liars were allowed to freely add details that could encourage the interviewer to believe them. Procedures where liars are provided with information they should use as the bases of a cover story (often a task completed by participants in a truth telling condition) are common in deception research (e.g., Nahari & Vrij, ; Granhag, Strömwall, & Jonsson, ; Porter et al, ; for a similar comparison, see Hudson, Vrij, Akehurst, & Hope, ).…”

Lying and memory in forensic interviews: The influence of voluntary deception and repeated interviews on memory for the truth

“…One technique that supports memory retrieval, reverse-order recall, has been shown to induce inconsistencies in both liars and truth-tellers (Gilbert & Fisher, 2006;Hudson et al, 2019). Hudson and colleagues examined consistency between two statements provided in close succession to each other (approximately 3 minutes following the conclusion of an initial interview).…”

“…would be sufficient to detect a small within-between interaction effect (f = .15) to achieve power of .90 with an alpha value of .05 (Faul, Erdfelder, Buchner, & Lang, 2009). This power analysis was based on the expected effect of Veracity x Volition, given the size of the main effect of Veracity in prior work (ds between 0.30 to 0.48 in Dianiska, Lane, et al, in prep) in concert with an expected small-to-medium influence of Volition (as found in Hudson et al, 2019). Due to computer errors, some data from Session 1 is missing for four participants who completed the full experiment, and data from Session 2 was lost for one participant.…”

“…would provide sufficient power to detect a relatively small within-between interaction effect size (f = .15) with power of .90 (Faul et al, 2009). This power analysis is based on prior work demonstrating differences in consistency for liars and truth-tellers across repeated interviews (e.g., f = .31 in Leins et al, 2012) and robust increases in total detail following strategic interviewing techniques (e.g., f = .20 when comparing chronological recall and reverse order recall in Hudson et al, 2019). To appropriately power an interaction between Veracity and Interview Technique, a more conservative effect size was used (f = .15) than has been observed in prior work.…”

“…empirically. For instance, some researchers have focused on inconsistency in terms of reminiscent items (Gilbert & Fisher, 2006), while others focused on consistency relative to contradictions provided (Leins et al, 2012), or simply the sum total of each type of (in)consistent detail (Hudson et al, 2019). For the current dissertation, I assessed the amount of consistent details provided, rather than proportion of consistent details relative to other information provided.…”