Nonverbal markers of lying during children’s collective interviewing with friends

To examine nonverbal behaviors that may differentiate between lie- and truth-tellers, recent studies have relied on collective interviews (e.g., Vrij and Granhag in Appl Cognit Psychol 28(6):936–944, 2014. https://doi.org/10.1002/acp.3071), where participants were solicited to fake their responses about an unexperienced event. In this study, we made participants experience actual events that involved a potential rule violation, and later interviewed them collectively and unanticipatedly about these previously experienced events. Ninety same-sex preschool dyads were observed in a temptation resistance paradigm, where an adult experimenter proscribed touching of attractive toys and left the children alone. The dyads of children were later interviewed by the experimenter about how they handled this rule. Nonverbal behaviors were coded during the entire interview phase where they could lie by withholding transgression (i.e., lying by omission) and right after a target question where children chose to lie or tell the truth (i.e., lying by commission). Truth-tellers and lie-tellers showed (1) differences in response latency, looking at friend, and use of gestures right after the target question, but were (2) similar in their interactive nonverbal behaviors during the entire interview (i.e., speech transition, looking at friend, and utterance rate). This is the first study showing that nonverbal behaviors accompanying lie-telling behavior are different when a collective interview is carried out in a spontaneous deceptive context as opposed to planned deceptive contexts.