How Do People Decide Which Experts to Trust?

A summary of the aim of modern propaganda is this: dictators don't do propaganda so people believe something but so they believe nothing. And more importantly, do nothing. In a modern society, no one individual is in a position to evaluate every scientific, medical, or political claim we hear, so we rely on experts. A central technique for saboteurs of public discourse is to undermine confidence in experts. It's therefore important to understand how people actually evaluate experts.

Hendriks, Kienhues and Bromme (2015) use the Muenster Epistemic Trustworthiness Inventory and show that people's evaluations are affected by three considerations: level of expertise, integrity, and benevolence. People are predisposed to discount any expert opinion that conflicts with their chosen moral authority. Consequently, it's not surprising that efforts to undermine experts frequently focus on integrity ("They're shills/they're only in it for the money" etc.)

This is an important tool not only for understanding propaganda attacks from Russia and other governments, but critically analyzing our own responses to expert opinions, especially ones we're inclined to disagree with. It also provides a way to understand why someone might listen to a celebrity instead of a scientist, if the belief in integrity and benevolence outweighs the expertise factor.


Hendriks F, Kienhues D, Bromme R (2015) Measuring Laypeople’s Trust in Experts in a Digital Age: The Muenster Epistemic Trustworthiness Inventory (METI). PLoS ONE 10(10): e0139309. https://doi.org/10.1371/journal.pone.0139309