100 Things Every Designer Needs to Know About People, 2nd Edition

37 People Screen out Information that Doesn’t Fit their Beliefs

Have you ever met someone who has a long-held belief that they just won’t change, no matter how much evidence you show them that the belief is not tenable? People seek out and pay attention to information and cues that confirm their beliefs. They don’t seek out—in fact, they ignore or even discount—information that doesn’t support what they already believe. This is called confirmation bias.

A confirmation bias is a type of “cognitive illusion.” People tend to pay attention to what they already believe and filter out information that doesn’t fit with their opinions and beliefs.

This can make it difficult to get someone to be willing to even read or listen to information that doesn’t ...