What behaviours might explain individuals’ perceived rapport in investigative interviewing? A round robin and behavioural coding study.

Objective: Limited work has investigated the effect that individual differences have on perceived rapport in mock investigative interviews. In order to address this gap, it is necessary to measure how witnesses’ perceptions of rapport may naturally differ when interacting with different interviewers. This study measures how mock interviewers and witnesses rate the level of rapport they experience, the impact of rapport on interview performance (account accuracy and detail), and finally, which interviewer and witness behaviours significantly influence rapport ratings.Methods: This study used a round robin methodology, whereby each interviewer (N=10) interviews each witness (N= 23) once about 10 different mock crime videos they had witnessed. Generating N= 202 total interviews. The mock investigative interviews were both audio and visually recorded. After each interview, both the interviewer and witnesses rated their own rapport experience of the interview. Later, the transcripts of the interviews were coded for detail and accuracy, and the videos were coded for rapport-relevant behaviours. Results: We found a weak positive association between interviewer and witness on some measures of rapport ratings, but little evidence of interviewer-witness overall agreement. Additionally, accuracy of information, word count and interview length were not associated with perceived rapport for the interviewer or witnesses. Finally, no relationship was found between specific coded behaviours and perceived rapport.Discussion: With limited agreement found between interviewer and witness perceptions of rapport, and no evidence of rapport-related behaviours influencing perceptions of rapport, there remains a gap in terms of what specific guidance may lead to supporting rapport experienced in interviewing. Further there may be questions about how participants respond to scales measuring rapport.