Lies in the lexicon: a corpus-based exploration of lexicon in truthful and deceitful narrative accounts

Abstract Corpus linguistic studies have shown that lexicon varies according to linguistic register, and cognitive studies have demonstrated that lexical aspects play a significant role in determining the veracity of people’s accounts. Both lines of research underpin the present study, where the aim is to explore how overall lexical properties (lexical density and lexical diversity, and noun, verb, and adjective density) are related to the veracity of narratives. We make use of a corpus of 576 spoken and written narratives, especially collected with the purpose of investigating linguistic properties in truthful and deceitful accounts. Data were collected in an experiment involving 36 participants who viewed four elicitation films depicting minor misdemeanors, and subsequently recounted the events in both written and spoken formats, resulting in four narrative accounts (two truthful and two deceitful, in which they were asked to alter a critical event regarding “who did it”). The results reveal some significant differences in how verb, noun, and adjective density relate to veracity, but the results are inconclusive. A cautious interpretation is that narrators make use of different lexical strategies depending on veracity but that elicitation material may strongly influence the effects, stressing the difficulties in characterizing deceptive written texts.