The persuasive effects of delaying identification of high- and low-credibility communicators: A meta-analytic review

A review of extant research evidence indicates that when source identification is delayed until after the message has been presented, the differential effectiveness of high‐ and low‐credibility communicators is reduced. In particular, those combinations of credibility level and advocated position that are ordinarily (i.e., with pre‐message identification) relatively advantageous (a low‐credibility source with a proattitudinal position, or a high‐credibility source with a non‐proattitudinal position) have persuasive effectiveness reduced by delayed identification, whereas those combinations that are ordinarily relatively disadvantageous (a high‐credibility source with a proattitudinal position, or a low‐credibility source with a non‐proattitudinal position) enjoy enhanced effectiveness with delayed identification. The magnitude of the effects associated with identification‐timing variations is quite large (mean absolute value of d = .753), at least by comparison to other factors for which quantitative estimates of persuasive effect are available. The observed effects place constraints on explanations of credibility's effects; in particular, credibility's effects cannot be explained through the mere association of a given communicator with a particular position.