Courage spreads the way yawns do. One person goes first and suddenly the whole row is brave.

Very few people want to be first at something visible and uncertain, and almost everyone is willing to be second. That is why one person going first changes a room so completely: it converts an unthinkable act into an obviously possible one, and the people who were already close to speaking suddenly have cover. The bravery does not spread because it is inspiring. It spreads because it lowers the cost.

Go first on something small this week. Ask the awkward question, volunteer, disagree once. Watch how fast somebody follows you.