While the brain is naturally inclined to think in negative terms as a defense mechanism, the habitual act of smiling helps the mind move to a more positive space and remain there longer the more you do it. According to Shawn Achor, the author of The Happiness Advantage, by making smiling a part of our everyday practice, we help our brains create happiness loops that encourage more positive-thinking patterns.

“Happiness is a work ethic,” wrote Achor. “It’s something that requires our brains to train just like an athlete has to train.”

Source:  The Huffington Post