Even if you look confident, I am not sure you are telling the truth! The role of sender confidence on truthfulness judgment of emotional narratives

Judging truthfulness and detecting deception are critical in the criminal justice system as well as in many other applied contexts (e.g., clinical and business organizations). The ability to discriminate a truth-teller from a liar might be associated with the content of deception (e.g., emotional or high-stakes lies) or with the deceiver's characteristics, such as his/her level of confidence shown in lying. The two present studies aimed to manipulate the level of the sender’s confidence and to investigate its effect in deception vs. truthfulness judgments of written narratives varying in emotional content. A pilot sample (N = 124) assessed the stimuli validity of sixteen written narratives (Study 1): 8 deceptive vs. truthful narratives x four types of content (i.e., emotional/bereavement vs. emotional/car accident vs. emotional/quarrel vs neutral/holiday) with low confidence in the recall and 8 deceptive vs. truthful narratives x four types of content (i.e., emotional/bereavement vs. emotional/car accident vs. emotional/quarrel vs neutral/holiday) high in the confidence recall. An experimental sample (N = 428) was administered the two sequences of eight written narratives and for each narrative, veracity judgment, detection accuracy, and judgment confidence were assessed (Study 2). We found that the sender’s confidence, the veracity, and the content of the narratives affected receivers’ veracity judgments and detection accuracy. High confidence made receivers prone to judge bereavements and holiday narratives as truthful and quarrels narratives as deceptive. In addition, high confidence made judgments more accurate for truthful narratives on holidays compared with others, and for deceptive narratives on car accidents and quarrels than for other narratives. The present results are discussed in light of their practical implications for the legal field.