Psychologists have an explanation for why crowds are prone to do stupid things at crucial moments. It can be action or inaction. But studies show people look to the actions of others to determine what the correct course of action is in an uncertain situation. It’s called social proof. You don’t want to look like an idiot, so you wait to see what everyone else is doing and go along. If everyone’s running up the street bashing windows, you’ll experience pressure to join in. On the other hand, if