Drop the small talk when establishing baseline behaviour in interviews

The present experiment investigated the behavioural patterns of interviewees when comparing their baseline behaviour, prior to the interview, with their behaviour during the investigative interview. Similar to what has been advised in the police literature, the truthful baseline behaviour was established prior to the interview through non-threatening questions. The investigative part of the interview then followed in which the interviewee was aware that they would be assessed on whether they were lying. During the investigative part, interviewees either discussed the job that they had (truth tellers, n = 128) or pretended to have (liars, n = 115). Findings revealed that both liars and truth tellers' behavioural patterns differed between the baseline behaviour and the investigative part of the interview. The findings suggest small talk should not be used as a baseline comparison with the investigative part of the interview when determining if the interviewee is being deceitful. An alternative way of using a baseline lie detection method, the comparable truth method, is discussed.