"The Quest to Bottle Happiness" in today's Orlando Sentinel details recent research into how we react emotionally to different smells:

For years, sensory scientists had assumed that our reactions to smell were hopelessly entwined with our cultural background. "When I came to the United Kingdom, I was shocked that the smell of chrysanthemums evokes romantic feelings in people here," says Phillipe Durand, a perfumer at fragrance development company Quest International in Ashford, Kent, England. "In France, we associate it with graves and death."

However, there is mounting evidence from brain scans that our responses to some smells, particularly bad ones, are innate, says Tim Jacob, a smell expert at Cardiff University in Wales. "That makes sense because if you had to wait and learn 'this smell kills you,' you'd be dead," he says.

Read the rest here. More reading: The Smell Report - Emotion, at the Social Issues Research Center; Smell, Emotion Processor In Brain May Be Altered In Depressed Patients at Science Daily.

Or skip the whole thing and just buy a bottle of Smiley.