For all of you seeking an image, symbol, or story to help you understand the mysteries of confirmation bias, I offer this YouTube presentation of a woman advocating for deer crossing signs to be moved to places safer for deer to cross. (sent to me by Steve Maybury, further confirming my sense of his humor)
 

"Underneath the many variations of collective folly lie at least two fundamental patterns that alert us to the potential of folly’s emergence. The first pattern is a movement toward separation and fragmentation. In this pattern, group members resist ideas, other group members, or other groups that are deemed “not me” or “not us.”

Sometimes this pull is subtle. Group members ignore divergent perspectives or data, welcoming only the data and perspectives that confirm what they know, or think they know. The cognitive sciences describe this behavior as confirmation bias—a tendency to search for and interpret information in ways that confirm our existing preconceptions."
~ Edited passage from The Power of Collective Wisdom: And the Trap of Collective Folly