Elevators present an uncomfortable situation of putting strangers into a temporary box.
People like to give each other plenty of space, with two people often standing on opposite sides of the elevator. The newest rider stands in the middle. Everyone scoots accordingly when the elevator gets too packed, avoiding each other like uncomfortable sardines.
Some people look at their phones to avoid making eye contact, getting so glued that they forget to push the elevator button. Others cough, fidget and act aloof to this uncomfortable but common social experiment that is the elevator ride.
The pursuit of quietness creates awkwardness. After all, an elevator ride is less than a minute, and chances are high you won't see the same people again.
The occasional small talk helps ease some of the tension. Trust fills the elevator. All of a sudden, it feels too early to say goodbye.
But as soon as the elevator doors open up, anonymity refreshes and life goes back to our private worlds.
Note: the same things above also happen on an escalator.