Celerity and Cajolery: Rapid Speech May Promote or Inhibit Persuasion through its Impact on Message Elaboration

The present experiment tests credibility-cue and elaboration likelihood (ELM) hypotheses about the effect of compressed speech on message-based persuasion. Participants heard either a proattitudinal or a counterattitudinal message on an involving topic, delivered at a slow (144 words per minute), an intermediate (182 wpm), or a rapid (214 wpm) rate of speech. Consistent with the ELM predictions, rapid speech suppressed the tendency to rebut the counterattitudinal message and enhanced persuasion, whereas the same rapid speech rate inhibited favorable elaboration of the proattitudinal message while undermining its persuasive impact. Thus, a distinctly faster than normal rate of speech on an involving topic can either promote or inhibit persuasion by its impact on message elaboration. The generality of these speech rate effects and the conditions under which rapid speech might serve as a peripheral (i.e., credibility) cue are discussed.