Clusters of Nonverbal Behaviors Differentiate Truths and Lies about Future Malicious Intent in Checkpoint Screening Interviews
Journal of Psychiatry, Psychology and Law, In Press
Recent research has shown that nonverbal behavior (NVB) assessed across multiple channels can differentiate truthtellers from liars. No study, however, has examined whether multiple NVB can differentiate truths from lies about intent for future malicious behavior, or across multiple culture/ethnic groups. We address this gap by examining truths and lies about intent to commit a malicious act in the future in brief, checkpoint-type security screening interviews. Data from four NVB channels producing 21 observable NVB were coded and analyzed using different analytic strategies. Clusters of NVB differentiated truthtellers and liars at statistically significant levels and substantially beyond that by human observers. These findings showed that clusters of NVB can differentiate truthtellers from liars even in brief, checkpoint interviews.
Clusters of Nonverbal Behaviors Differ According to Type of Question and Veracity in Investigative Interviews in a Mock Crime Context
Journal of Police and Criminal Psychology, December 2017
Evaluating truthfulness and detecting deception is a capstone skill of criminal justice professionals, and researchers have long examined nonverbal cues to aid in such determinations. This paper examines the notion that testing clusters of nonverbal behaviors is a more fruitful way of making such determinations than single, specific behaviors. Participants from four ethnic groups participated in a mock crime and either told the truth or lied in an investigative interview. Fourteen nonverbal behaviors of the interviewees were coded from the interviews; differences in the behaviors were tested according to type of question and veracity condition. Different types of questions produced different nonverbal reactions. Clusters of nonverbal behaviors differentiated truth tellers from liars, and the specific clusters were moderated by question. Accuracy rates ranged from 62.6 to 72.5% and were above deception detection accuracy rates for humans and random data. These findings have implications for practitioners as well as future research and theory.