This study examined the effects of background nonverbal behavior displayed with the purpose of undermining one's opponent in televised debates. Students watched one of four versions of a televised debate. In each, while the speaking debater appeared on the main screen, subscreens displayed her nonspeaking opponent's background nonverbal behavior. In one version, the non-speaking debater remained “stone faced” during her opponent's speech, while in the other three she nonverbally displayed occasional disagreement, nearly constant disagreement, or both agreement and disagreement. After viewing the debates, students rated the debaters' credibility, appropriateness, objectivity, and debate skills, in addition to judging who won the debate. Analysis indicated that background nonverbal behavior influenced audience perceptions of debaters' credibility, appropriateness, objectivity, debate skill, and the extent to which the debate was won. These results suggest that adding nonverbal agreement to expressions of nonverbal disagreement do not reduce the negative impacts of communicating disagreement nonverbally during an opponent's speech and may in fact further decrease the audiences' perception of a debater's credibility and overall performance.