This is a very readable book that looks at the messengers rather than the message, and how some types of messenger are more effective than others. They identify eight factors that influence who gets listened to and who is ignored, including appearance and financial status, which are often more important than the wisdom of the messenger.
Of course, trust is very important in determining who we pay attention to and the authors outline harder and softer ways to do this. Hard messengers rely on status, expertise, power or appearance, while soft messengers rely on warmth, vulnerability, trustworthiness or charisma. These eight factors correspond to many well-known “cognitive biases”, and rely on perceptions of the messenger rather than the reality (this is especially important as charisma and confidence often override real expertise).
Trustworthiness is a particularly important trait, and the authors argue that trust is mostly based on two pillars: competence and integrity. Interestingly, recent work by Edelman has shown that integrity is much more important than trust in shaping perceptions of brand trust, and it would be interesting to know if this applies to messengers too (I suspect it does, as seen in recent events).
This is an interesting read for anyone interested in advertising, communication, and behaviour change, and resonates with work that I have done in Indonesia (link) and Thailand (link) on the use of celebrities and influencers in advertising. Sometimes relatability is much more important than “fame” in building trust.