TMI? Accompanying details impact statements’ perceived veracity.

Abstract

Deception is a ubiquitous part of human interaction. However, discriminating between truthful and deceptive statements is an arduous task. Research has shown that truthful and deceptive accounts vary the type of content provided, suggesting that verbal cues are a diagnostic approach when discerning statement veracity. The present studies examine participants' expectations regarding what content is believed to be present in both truthful and deceptive statements. Specifically, we examined how different types of accompanying information impact statement believability. Participants read statements that varied in the content that was presented and indicated whether they believed the statement to be truthful or deceptive. Additionally, we manipulated consequence severity. Some participants were told that the statement provider had a high incentive to lie while others were told that there was a low incentive. Across both experiments, we observed that certain types of additional information decreased statement believability. Specifically, statements that included a personal qualification or an excuse were more likely to be perceived as being deceptive than statements that did not contain additional details or contained details specific to the task. This finding was true regardless of consequence severity. These findings suggest that not all accompanying details increase credibility and are discussed through the lens of Gricean maxims as well as other theories of deception detection. Public Significance StatementResearch has shown that people perform poorly when distinguishing truthful from deceptive statements. The present studies explore how additional accompanying information may make a statement appear more or less believable. The results from these studies found that statements that included details about the speakers' personal character or an excuse were more likely to be judged as deceptive compared to statements that had minimal information or details specific to the task. Information about the situational factors did not seem to impact these judgments.