Turn That Frown Upside Down!

Why? Smiling makes your brain release "happy" chemicals, says Stanford psychology professor Robert Zajonc. His theory, backed by studies at Germany's Mannheim University; when you smile, you breathe through your nose while putting pressure on certain facial muscles. This cools the blood that travels to the hypothalamus, which releases feel-good endorphins. (Positive Thinking March/April 2008)