Lie detection research comparing manual and automated coding of linguistic cues is limited. In Experiment 1, we attempted to extend this line of research by directly comparing the veracity differences in manual coding and two coding software programs (Text Inspector and Linguistic Inquiry and Word Count [LIWC]) on the linguistic cue “total details” across eight published datasets. Mixed model analyses revealed that LIWC showed larger veracity differences in total details than Text Inspector and manual coding. Follow-up classification analyses showed that both automated coding and manual coding could accurately classify honest and false accounts. In Experiment 2, we examined if LIWC’s sensitivity to veracity differences was the result of honest accounts including more redundant (repeated) words than false accounts as LIWC—but not Text Inspector or manual coding—accounts for redundancy. Our prediction was supported, and the most redundant words were function words. The results implicated that automated coding can detect veracity differences in total details and redundancy, but it is not necessarily better than manual coding at accurately classifying honest and false accounts.

Despite its controversial status, the lie detection test is still a popular organizational instrument for credibility assessment. Due to its popularity, we examined the effect of the lie-detection test feedback on subsequent moral behavior. In three studies, participants could cheat to increase their monetary payoff in two consecutive phases. Between these two phases the participants underwent a mock polygraph test and were randomly given Deception Indicated (DI) or No Deception Indicated (NDI) assigned feedback. Then, participants engaged in the second phase of the task and their level of dishonesty was measured. Study 1 showed that both NDI and DI feedback (but not the control) reduced cheating behavior on the subsequent task. However, Study 2 showed that the mere presence of the lie-detection test (without feedback) did not produce the same effect. When the role of the lie detector as a moral reminder was cancelled out in Study 3, feedback had no effect on the magnitude of cheating behavior. However, cheaters who were given NDI feedback exhibited a lower level of physiological arousal than cheaters who were given DI feedback. These results suggest that lie detection tests can be used to promote honesty in the field, and that, while feedback type does not affect the magnitude of cheating, NDI may allow people to feel better about cheating.

Recent criminal psychology research has raised critical questions about applying non-verbal communication methods for lie detection purposes in forensic settings. Research has shown low correlations between non-verbal communication and deception. However, non-verbal communication methods are still widely applied and suggested by police manuals. Results obtained by experimental and field research are biased by the following factors: (i) attention is given only to quantitative aspects of non-verbal behavior; (ii) there is a lack of research of qualitative aspects related to non-verbal behavior analysis; (iii) lack of connections between non-verbal indicators and verbal content; (iv) lack of attention on timing of non-verbal behavior; (v) most research is performed on psychology students in experimental contexts. This article proposes a new methodology for applying the Facial Action Coding System as investigative support and not as a lie detection method. The Facial Action Coding System will be introduced to integrate with verbal content analysis and a new framework to interpret non-verbal signs discussed. The aid of standardized non-verbal methods will be discussed through an in-depth psychological analysis of a case of homicide perpetrated in 2010 in Southern Italy by discussing a video analysis of the suspects’ statements.

The deception literature has predominantly focused on detection of guilty individuals using electrodermal measures. Little research has examined other psychophysiological measures or the mechanisms underlying deception. Therefore, the present study examined pupillary responses in a differentiation-of-deception paradigm. Twenty-four undergraduate participants answered the same questions twice, once truthfully and once deceptively, while pupillary responses were recorded. Questions were based on recently learned (episodic) information from scenarios or on general (semantic) knowledge from long-term memory. Task-evoked pupil dilation was significantly greater when participants confabulated responses than when they told the truth for both episodic and semantic memory questions. Previous research has demonstrated that pupil size increases with increased cognitive processing load. The present study suggested that generating deceptive recall was associated with increased pupil size and required greater cognitive processing than truthful recall.