Messenger Effect

What is the messenger effect?

The messenger effect is a broad label for differences in how a message is received because of who appears to deliver it. Relevant characteristics can include perceived expertise, trustworthiness, or similarity. The same claim can receive a different hearing from a trusted colleague than from an unknown advertiser.

A meta-analysis by Kumkale, Albarracín, and Seignourel (2010) examined source credibility in persuasion. Its relationship with recipients’ ability and motivation to process a message depended on whether they had prior attitudes. Some source-based effects also decayed quickly.

Source information is not automatically an irrational bias: expertise can be relevant to evaluating a claim. But a trusted messenger does not make an inaccurate statement true. An attitude change also does not establish a change in behavior. Someone can like or believe a message without doing what it asks.