Strategic Synchrony and Rhythmic Similarity in Lies About Ingroup Affiliation

In an attempt to enhance the likelihood that a lie is perceived as truthful, deceivers might strategically attempt to build rapport in an interaction. Deceivers can build this rapport by coordinating behaviors with their interaction partners, thereby creating interpersonal synchrony. The goal of this study was to empirically test whether deceptive message senders strategically synchronize their behaviors with those of their receivers when speaking with an ingroup member about ingroup affiliation—where deception is not expected. We employed a 3 × 2 factorial design ( N = 222 valid cases) in which the level of involvement enacted by partner one (high, low, or control) and the veracity of claims made by partner two (truth or deception) were manipulated. This paper discusses three findings that were observed in this study: (1) Consistent with the truth bias, most people perceived their partner as truthful (84%) or were unsure of the partner’s truthfulness. (2) Contrary to expectations, interaction partners rated deceivers lower than truth tellers in rapport and synchrony, but results indicated that greater involvement was related to increased synchronization and rapport. (3) Finally, both trained coders and automated spectrum analysis observed almost no difference between deceivers and truth-tellers in the interaction behaviors, but deceivers showed more synchrony in their faster movements. This demonstrates a relationship between synchrony and deception that can only be observed via automated analysis, suggesting an important avenue for future research.