Elevator wars

What is it about the nature of the elevator interior that demands total silence and complete termination of all previous form of communication?
The area in front of the elevator is an extroverts paradise. Work mates clutch cups of expensive, hot starbucks coffee, weekends are described, new shoes, jewelry and other such adornments appraised. Life is good, and high powered executive frolics with lowly janitor. Buttons are pressed, the wonder of being at work is discussed, and all is well.
Then a light flashes. Ding! A slight shift in the air, and people regard each other, stealing furtive glances from under lowered lashes. An almost imperceptible spirit visible only to the trained eye has possessed this group. It reveals itself in the clenched buttock, in the tightening of the jaw, the faltering conversation.
The doors open, and each walks into his own private territory. A little to the left, a bit to the back. Muttered excuse me's and sorry's are exchanged. Place feet appropriately and stance.
In a second, the elevator doors glide towards each other and shut.
And there is silence.
1 - ding
2 - ding
Shoes are examined. Quality mentally assessed and prices calculated. That one over there shops at Walmart. That one over here shops at JC Penny. Not me, I shop at Saks. Noses turn upward as if seeking the air that is purest and untainted.
3 - ding
Eyes ever forward, faces composed, eyes unyielding. It is the great elevator undertaking. Be cool. Be sauve.
4, 5 - ding, ding. People get off.

And down again.