Self‐reported cues about deceptive and truthful communication: The effects of cognitive capacity and communicator veracity

One hundred four students watched a videotape of six communicators (three liars and three truthtellers) and were asked to judge the veracity of the strangers’ communication. In addition to judging deception, students reported which cites guided their veridical judgments. To limit their available cognitive capacity one‐half of the participants were given an additional cognitive task to complete (counting backwards from a number by 7) while viewing the videotapes. Results indicated that lie detectors with limited cognitive capacity reported using more vocal cues and fewer verbal cues than lie detectors whose cognitive capacity was not manipulated. Lie detectors with limited capacity were more accurate at catching liars and reported fewer truthful judgments than lie detectors in the high capacity condition. Overall, lie detectors reported using primarily demeanor cues and visual cues to distinguish truths from lies. Results also indicated that lie detectors’ beliefs about deception differed as a function of the communicators’ veracity. Specifically, when judging truthful communicators, lie detectors reported using fewer vocal cues and demeanor cues while relying on a greater number of verbal and visual cues as compared to lie detectors judging deceptive communicators.