Silent derogation and perceptions of deceptiveness: Does communicating nonverbal disbelief during an opponent's speech affect perceptions of debaters’ veracity?

Compared to televised debates using a single‐screen presentation, those using a split screen presenting both debaters simultaneously show viewers the nonverbal reactions of a debater's opponent. This study examined the effect of such reactions on viewers’ ratings of both the speaker's and the nonverbal communicator's veracity. Students watched one of four versions of a televised debate. One version used a single‐screen presentation, showing only the speaker, while the other three versions used a split‐screen presentation in which the speaker's opponent displayed constant, occasional, or no nonverbal disbelief regarding the content of the speaker's message. After watching the videos, students rated the veracity of the debaters’ communication. Analysis indicated that when the nonspeaking debater showed constant signs of disbelief, his communication was perceived as deceptive, while his opponent's communication was perceived as truthful. Moderate signs of disbelief lowered truthfulness ratings for both debaters’ communication. These results and their implications are discussed.