Does Communicating Nonverbal Disagreement during an Opponent's Speech Affect the Credibility of the Debater in the Background?

Abstract

Compared to televised debates using a single-screen format, 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 nonverbal reactions on viewers' ratings of the nonverbal communicator's credibility. Students watched one of four versions of a televised debate. One version used a single-screen format, showing only the speaker, while the other three versions used a split-screen format in which the speaker's opponent displayed constant, occasional, or no nonverbal disagreement with the speaker. After watching the videos, students rated the opponent's credibility using the Source Credibility Scale of McCroskey, et al. Analysis indicated that nonverbal disagreement by the nonspeaking debater, especially when constant, lowered his ratings of competence, composure, and sociability, while constant disagreement decreased his ratings of character while increasing his ratings of extroversion. These results and their implications are discussed.