The Happiness Advantage: The Seven Principles of Positive Psychology That Fuel Success and Performance at Work. By Shawn Anchor

This is the first book I read that focuses solely on happiness and, more specifically, on strategies for happiness. Like the other books on this list, it prompted a powerful shift in my mindset. Shawn Anchor begins with the startling (at least to me) concept that success doesn’t create happiness, but that happiness leads to productivity, better health, and deeper relationships. A deep-rooted belief in your own ability to change is a central part of happiness, and the best leaders focus on the potential of each team leader.