The Influence of Source Credibility on Attitude Certainty: Exploring the Moderating Effects of Timing of Source Identification and Individual Need for Cognition

This research investigates the influence of source credibility on attitude certainty, referring to an individual’s subjective confidence in his/her attitude. Results of a laboratory experiment (N 220) show that low source credibility, compared with high source credibility, leads to greater attitude certainty. This relationship, however, only holds when the source is identified before message exposure and for people who are low in need for cognition. Theoretical and practical implications of the findings are discussed. © 2009 Wiley Periodicals, Inc. Recent developments in persuasion research suggest that attitudes that are equally favorable may differ in their underlying strength. In other words, some attitudes are inherently “stronger” than others, even though they all possess the same degree of favorablility. Attitudes with greater strength are said to be more persistent over time, more resistant to attack, and more predictive of Psychology & Marketing, Vol. 26(4): 321–332 (April 2009) Published online in Wiley InterScience (www.interscience.wiley.com) © 2009 Wiley Periodicals, Inc. DOI: 10.1002/mar.20275