It is illegal to converse in an elevator.

The Law Explained

An old, unwritten rule of etiquette that somehow found its way into obscure city ordinances dictates that people should face forward and keep quiet in elevators. Originally, this was meant to maintain decorum and personal space in the newly invented, tightly packed contraptions. While never practically enforced, maintaining stoic silence while staring at the floor numbers is still the preferred New Yorker way.