Truth tellers reported more verifiable digital details & sources than liars; also provided more unverifiable detail than liars, which was not predicted & goes against the findings in previous studies

Fading lies: applying the verifiability approach after a period of delay. Louise Marie Jupe,Aldert Vrij,Sharon Leal & Galit Nahari. Psychology, Crime & Law, Sep 25 2019. https://doi.org/10.1080/1068316X.2019.1669594

ABSTRACT: We tested the utility of applying the Verifiability Approach (VA) to witness statements after a period of delay. The delay factor is important to consider because interviewees are often not interviewed directly after witnessing an event. A total of 64 liars partook in a mock crime and then lied about it during an interview, seven days later. Truth tellers (n = 78) partook in activities of their own choosing and told the truth about it during their interview, seven days later. All participants were split into three groups, which provided three different verbal instructions relating to the interviewer’s aim to assess the statements for the inclusion of verifiable information: no information protocol (IP) (n = 43), the standard-IP (n = 46) and an enhanced-IP (n = 53). In addition to the standard VA approach of analysing verifiable details, we further examined verifiable witness information and verifiable digital information and made a distinction between verifiable details and verifiable sources. We found that truth tellers reported more verifiable digital details and sources than liars.

KEYWORDS: Deception, verifiability approach, investigative interviews, delay

---
We also found that truth tellers provided more unverifiable detail than liars, which was not predicted and goes against the findings in previous studies. We are unable to explain these different findings in our experiment compared to previous work. It could be related to the delay, but to test this an immediate condition needs to be included in the design. One of our initial aims was to see if the VA was still applicable in delay conditions. We did not include an immediate condition as we did not expect significant differences between the immediate and delay conditions. With hindsight, an immediate condition should have been included.