A perceptual and behavioral analysis of facial cues to deception in interactions between children and a virtual agent

This study focused on the facial expressions that children exhibit while trying to deceive a virtual agent. An interactive lie elicitation game was developed to record children's facial expressions during deceptive and truthful utterances. Our participants did this task either alone or in the presence of peers. A manual method and an automatic recognition approach were used to examine facial expressions and facial action units (AUs). Results show that the facial expressions of deceivers differ from those of truth-tellers: most clearly, they try to cover their lie as they smile significantly more often than truthful children. Moreover, co-presence enhances children's facial expressive behavior and the number of deceptive cues. To understand whether such features serve as cues for deception detection, using data from children playing alone or together with another child, a perception test was carried out to examine observers' ability to distinguish young deceivers from truth-tellers. Results show that observers found it easier to discriminate between deceivers and truth-tellers who had played the game in the co-present condition. Our research thus shows that virtual agents can be used as tools to elicit lies in a playful manner, which would be relevant for developmental, educational and behavioral analyses of deceit in growing children.