Individual Differences in the Shift-of-Strategy Approach

The Shift-of-Strategy (SoS) approach uses strategic interviewing to induce a change in counter-interrogation strategies of suspects. When suspects switch from denial or avoidance to a more forthcoming strategy, the interviewer is able to gather more information about the event in question. This shift can occur when the suspect believes that the interviewer has more knowledge about their actions than they previously assumed. Suspects’ behaviour may also be affected by individual differences in personality traits. This study examined how counter-interrogation strategies used by suspects are associated with their levels of neuroticism, conscientiousness, extraversion, psychopathy, narcissism and Machiavellianism. To test this participants watched a mock crime video in the first-person perspective, took part in an online interview (Direct or SoS) about their activities and completed the 50-item IPIP version of the NEO-PI-R and the Dirty Dozen. For the analysis several linear mixed regressions and a latent class analysis were conducted. The results show a negative interaction between interview condition (SoS) and neuroticism, conscientiousness, extraversion as well as Machiavellianism on the consistency of disclosed information. Additionally, a positive interaction between interview condition (SoS) and narcissism was found. There was no significant interaction effect between interview condition and psychopathy. The latent class analysis revealed that Machiavellianism and its interaction with interview condition did not differ substantially between the two classes that were found. The results suggest that the SoS approach can increase consistency among guilty suspects. However, this effect seems to vary based on whether participants score high or low on specific personality traits.