Speed of Speech and Persuasion: Evidence for Multiple Effects

This study examined the possibility that increased speech rate can affect persuasion either by acting as an agreement cue or through its impact on message processing. Participants heard messages that were either moderate or high in personal relevance, consisted of weak or strong arguments, and were presented at either moderate (180 words per minute) or fast (220 wpm) rates of speech. Consistent with hypotheses derived from the elaboration likelihood model, fast speech served to inhibit participants' tendency to differentially agree with strong versus weak message arguments under both moderate and high relevance. However; fast speech was associated with increased persuasion only for moderate involvement subjects, and this influence was mediated by perceptions of source credibility. Polarity of message-based elaborations predicted attitudes of both moderately and highly involved subjects. Thus, central and peripheral route processes appeared to be co-occurring for moderately involved participants.