‘Richness-in-detail’ as a veracity cue
: examining the impact of suboptimal recall contexts

  • Adam Harvey

Student thesis: Doctoral Thesis

Abstract

The aim of this thesis is to explore the impact of suboptimal recall contexts upon the utility of the popular verbal veracity cue ‘richness-in-detail’. Six experiments examined two factors that attenuate the extent to which detail might be used to distinguish between genuine and fabricated statements: (i) delay (i.e. the time between encoding and being interviewed about an event), and (ii) truth-tellers’ encoding quality (i.e. if events are encoded by truth-tellers incidentally, or intentionally). Chapter 1 introduces richness-in-detail as a verbal veracity cue and explores the theoretical impact that delay and encoding quality may have on suspects’ recollection of detail. Chapter 2 comprises two experiments and examines whether lie-tellers can accurately feign the tendency for truth-tellers to forget after a delay. Both experiments showed that regardless of whether lie-tellers incorporated a delay into their statements using their imagination (Experiment 1) or using an actual experience (Experiment 2), they failed to accurately feign the effects of forgetting. Chapter 3 consists of Experiment 3 and examines the effect of encoding quality and delay on the verbal accounts of truth-tellers and lie-tellers. All truth-tellers reported fewer details after a delay (cf. immediately) whereas lie-tellers reported equivalent detail when interviewed immediately or after a delay. No differences by veracity group emerged for reported detail after the delay. Chapter 4 consists of Experiment 4 and examines whether a Model Statement facilitated lie-detection when interviewing took place after a three-week delay. In the Immediate interviewing condition, irrespective of the Model Statement, truth-tellers provided more details than lie-tellers. In the Delayed interview condition, truth-tellers and lie-tellers reported a similar amount of detail in the Model Statement-absent condition, whereas in the Model Statement-present condition (in a reversal of the typical findings regarding detail) lie-tellers reported more details than truthtellers. Chapter 5 consists of Experiment 5 and examines whether initial interviewing facilitated lie-detection using the richness-in-detail cue when (i) truth-tellers’ attention during encoding was manipulated and (ii) interviewing occurred after a three-week delay. Truth-tellers in the initial interview-present (versus absent) condition reported more detailed statements after three weeks irrespective of encoding quality. Lie-tellers’ statements were unaffected by initial interviewing condition. Chapter 6 consists of Experiment 6 and examines the mechanism underlying the stability bias effect amongst lie-tellers. Although participants correctly predicted that forgetting would occur after delays, their predictions regarding how much detail should be included to appear convincing were insensitive to the effects of delay. Our findings are consistent with the stability bias effect being driven by lie-tellers’ strategic motivation to appear convincing. Theoretical and practical implications of the findings are discussed, and future research directions suggested in Chapter 7.
Date of AwardJun 2021
Original languageEnglish
SupervisorAldert Vrij (Supervisor), Lorraine Hope (Supervisor) & Sam Mann (Supervisor)

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