The illusion of consensus is powerful. Here’s why you should fight it.

The illusion of consensus is powerful. Here’s why you should fight it.

It’s the spring of 1951. As the Korean War escalates and the world engages in scandalized debate over Julius and Ethel Rosenberg’s recent conviction for espionage, students at Swarthmore College in Pennsylvania are gathering in small groups to take part in what they believe to be a vision test. They’re shown three lines of obviously different lengths and asked which one matches a target line. Unaware that they’re participating in a psychology ex…