Learning to Detect Deception from Evasive Answers and Inconsistencies across Repeated Interviews: A Study with Lay Respondents and Police Officers

Abstract

Previous research has shown that inconsistencies across repeated interviews do not indicate deception because liars deliberately tend to repeat the same story. However, when a strategic interview approach that makes it difficult for liars to use the repeat strategy is used, both consistency and evasive answers differ significantly between truth tellers and liars, and statistical software (binary logistic regression analyses) can reach high classification rates (Masip et al., 2016b). Yet, if the interview procedure is to be used in applied settings the decision process will be made by humans, not statistical software. To address this issue, in the current study, 475 college students (Experiment 1) and 142 police officers (Experiment 2) were instructed to code and use consistency, evasive answers, or a combination or both before judging the veracity of Masip et al.'s (2016b) interview transcripts. Accuracy rates were high (60% to over 90%). Evasive answers yielded higher rates than consistency, and the combination of both these cues produced the highest accuracy rates in identifying both truthful and deceptive statements. Uninstructed participants performed fairly well (around 75% accuracy), apparently because they spontaneously used consistency and evasive answers. The pattern of results was the same among students, all officers, and veteran officers only, and shows that inconsistencies between interviews and evasive answers reveal deception when a strategic interview approach that hinders the repeat strategy is used.

Veracity is in the eye of the beholder: A lens model examination of consistency and deception

“…The consistency heuristic is used to inform veracity judgements when examining multiple interviewees' statements (Strömwall, Granhag, & Jonsson, 2003), when examining the consistency within statements (Reinhard, Greifeneder, & Scharmach, 2013), and when comparing interviewee statements to evidence (Hartwig, Granhag, Strömwall, & Vrij, 2005). The consistency heuristic has been mostly examined in relation to multiple statements taken from the same individual (Granhag & Strömwall, 2000; Masip et al, 2018; Strömwall & Granhag, 2003). To date there is little research examining whether people actually use the consistency heuristic when making veracity judgements across multiple statements, or whether they simply report it as a perceived cue to deception.…”

“…One of the most commonly reported verbal cues to deception is between‐statement (in)consistency (Granhag & Strömwall, 2000, 2001); reported by both laypeople (Krix, Sauerland, Lorei, & Rispens, 2015) and legal professionals (Strömwall & Granhag, 2003). When examining the perceptions of the deception‐consistency relationship amongst uninformed laypeople and investigators, Masip et al (2018) found that uninformed laypeople who were asked to make veracity judgements on a series of written statements most commonly reported (90%) utilising (in)consistency to assist in making their judgement.…”

“…As not all judges interpret cues equally, and in turn, not all statements contain all cues, using a within subjects repeated measures design we account for the variance that is contributed by the judge (i.e., a participants' personal beliefs about consistency and deception) as well as the statement. Given the widely reported use of between‐statement consistency to inform veracity judgements (Granhag & Strömwall, 2001; Masip et al, 2018; Strömwall & Granhag, 2003), it was predicted that participants will use the consistency heuristic to inform their credibility assessments. As such, participants' perception of between‐statement consistency will influence their veracity judgements such that statements that are perceived to be higher in consistency will be rated significantly more truthful than statements that are lower in consistency (Hypothesis 1).…”

An examination of the Self‐Administered Interview as a verbal veracity assessment tool

“…With research indicating that truth tellers report more details than liars (Amado et al, 2016; DePaulo et al, 2003), it was predicted that truth tellers would include significantly more repetitions in their subsequent interview than liars, particularly if they initially completed the SAI, as they would have initially reported more details which they could repeat (Hypothesis 3). It was also predicted that as reminiscences are commonly found in repeated honest recalls (Fisher et al, 2009; Gilbert & Fisher, 2018; Strange et al, 2014), truth tellers will include significantly more reminiscences in their subsequent interview than liars, who may avoid including new information, as they wish to be perceived as consistent (Granhag & Strömwall, 1999), particularly if they initially completed the SAI (Hypothesis 4). Liars may feel that by completing the SAI, they have already provided an adequately detailed account and be reluctant to expand their statement further, in an effort to keep their story simple (Granhag & Strömwall, 2002; Hartwig, Granhag & Strömwall, 2007).…”

“…Granhag et al (2016) also found that the consistency of truth tellers and liars was similar when examining repetitions, reminiscences and omissions. Yet when Masip et al (2018) asked uninformed laypeople to make veracity judgements on a series of written statements, they found that 90% of the laypeople reported using consistency/inconsistency to assist in making their judgement. This is incongruous with research examining truth tellers' and liars' consistency, as well as memory research, which suggests that some types of inconsistencies, such as omissions and reminiscence, are commonly found in memory accounts (Fisher, Brewer & Mitchell, 2009; Gilbert & Fisher, 2006; Strange, Dysart, & Loftus, 2014).…”