Children's Facial Expressions in Truthful and Deceptive Interactions with a Virtual Agent

The present study focused on the facial expressions that children exhibit while they try to deceive a virtual agent. An interactive lie elicitation game was developed to record children's facial expressions during deceptive and truthful utterances, when doing the task alone or in the presence of peers. Based on manual annotations of their facial expressions, we found that children, while communicating with a virtual agent, produce different facial expressions in deceptive and truthful contexts. It seems that deceptive children try to cover their lie as they smile significantly more than truthful children. Moreover, co-presence enhances children's facial expressive behaviour and the amount of cues to deceit. Deceivers, especially when being together with a friend, more often press their lips, smile, blink and avert their gaze than truth-tellers.