"She responded very well to that, " he said, smiling and even tearing up a bit.

CNN: STORY HIGHLIGHTS

The secrecy was serious: when he spoke of spirits, his smiling face became deadly sober and even scared.

ECONOMIST: Mau Piailug

"We saw a steeper decline in heart rate and a faster physiological stress recovery when they were smiling, " even though the participants weren't aware they were making facial expressions, says Sarah Pressman, co-author of the study and an assistant psychology professor at University of California, Irvine.

WSJ: Stress-Busting Smiles

Yet, even in a wheelchair, Sara would always arrive smiling, makeup on and bangs bobby-pinned out of her eyes.

NEWYORKER: Letting Go

Even bankers were smiling, including chief marketing officer Arun Sinha of Zurich and chairman and CEO Jamie Dimon (above right, with Steve Forbes) of JP Morgan Chase.

FORBES: Where Do Bankers Smile? On The Davos Party Circuit

Nevertheless, as I walk through the corridors of business organizations, enter meetings that are about to begin, embark on various modes of transportation and even engage with the host or hostess in a restaurant, I rarely see people smiling.

FORBES: New Data on Smiling

She even stopped the tour at one point to back track down a hallway and sneak into a jazz rehearsal, smiling broadly before slipping inside the room for a few moments to listen.

FORBES: Carla Bruni-Sarkozy On Art, Philanthropy