The impact of information and setting on detection of deception by police detectives

Previous research shows that observers are hardly able to detect deception above the level of chance. The literature reveals several suggestions on how to improve the detection of deception. In this experiment the impact of four suggestions was tested. According to two suggestions the accuracy rate will improve if observers are provided with relevant information, such as (1) information about indicators of deception, or (2) outcome feedback. The two other suggestions emphasize that detecting deception is easier under certain circumstances than under others, that is, (3) spontaneous interviews are more detectable than planned interviews, and (4) the presence of comparison with a baseline facilitates the detection of deception. In the present experiment 360 police detectives assessed subjects' veracity on the basis of short videotaped interviews. Detectives watched the clips in one of 12 conditions formed by the crossing of four levels of setting (one spontaneous interview/one planned interview/two interviews-total image/two interviews-hands only) with three levels of information (no information/information about objective indicators of deception/information about objective indicators of deception plus feedback). Results revealed that information improved detection of deception, but only in the planned interview condition and the two interviews-hands only condition.This study was supported by a grant from the Recherche Advies Commissie (RAC) of the Ministry of Justice.