The relationship between people's beliefs and their actual lying behaviour has received minimal attention in the literature. In the current study, we examined whether people's beliefs about vocal pitch were related to their pitch behaviour during deception. Thirty-nine university students participated in audio-taped interviews where, in a within-subjects design, both their true and false opinions of common social issues were elicited. Vocal pitch (fundamental frequency; F0) was calculated for each audio sample. Following the interview, participants completed a questionnaire designed to determine their beliefs about the behavioural indicators of deception. It was found that participants' pitch increased when they lied. Furthermore, participants who believed that pitch increases during deception, produced significantly higher pitch in their lying compared to their truthful utterances. Importantly, these findings emphasise the utility of pitch as a marker of deception because it may be less susceptible to behavioural control than physical markers such as gaze behaviour.
- beliefs about lying behaviour
- fundamental frequency
- linguistic markers of deception