Effects of preconceptions on deception detection and new answers to why lie-catchers often fail

Abstract

This study investigated the extent to which crediting and discrediting background information, given to observers before they watched three video-taped interviews with the same witness, affected their veracity judgments. Our analyses show that the observers' distribution of truth/lie-judgments were more affected by crediting than discrediting background information. We also mapped the subjective cues given to justify the truth/lie-judgments, and found that the most frequently used cue was whether or not the three statements were consistent over time. In addition, our analysis revealed two types of inter-observer disagreements. One type referred to how different cues were perceived (e.g., forty observers perceived the three statements as being inconsistent over time while an equal number perceived the same three statements as being consistent over time). The second type referred to how different cues were used (e.g., the fact that the witness was perceived as not being confident in his testimony worked against him equally as often as it worked for him).