Producing deceit: the influence of veracity on linguistic processes in speaking and writing

Abstract This experimental study explored how adopting a deceptive stance affects linguistic processes during real-time production of multi-sentence texts in speaking and writing. Language production involves planning, monitoring and editing – processes that give rise to and are shaped by fluctuations in processing demands. Deception is assumed to influence these processes as speakers and writers manage competing communicative goals: to be coherent while concealing the truth. Narratives were elicited by asking participants to account for events from four short films: two truthful and two deceitful, in both speaking and writing. In speaking, deception decreased the total number of pauses, but in longer deceptive texts, pausing instead increased, suggesting adaptive adjustments to regulate overt cues to lying. In writing, deception decreased text revisions and altered pause behaviour, suggesting that writers modified their production patterns when altering information. Together, these findings suggest that deceptive language production involves shifts in planning, monitoring and editing processes that manifest differently across modalities: while speech shows suppression of pauses, writing reveals subtle changes in revision and pausing behaviour. These results highlight modality-specific signatures of deception and demonstrate how speakers and writers dynamically adapt their language production processes to align with communicative intent.