We've all been told that thinking rationally is the key to success. But at the cutting edge of science, researchers are discovering that feeling is every bit as important as thinking.

You make hundreds of decisions every day, from what to eat for breakfast to how you should invest, and not one of those decisions would be possible without emotion. It has long been said that thinking and feeling are separate and opposing forces in our behavior. But as Leonard Mlodinow, the best-selling author of Subliminal, tells us, extraordinary advances in psychology and neuroscience have proven that emotions are as critical to our well-being as thinking.

How can you connect better with others? How can you make sense of your frustration, fear, and anxiety? What can you do to live a happier life? The answers lie in understanding your emotions. Journeying from the labs of pioneering scientists to real-world scenarios that have flirted with...