Research shows that when people work with a positive mind-set, performance on nearly every level – productivity, creativity, engagement - improves. Yet happiness is perhaps the most misunderstood driver of performance. For one, most people believe that success precedes happiness. “Once I get a promotion, I'll be happy,” they think. Or, “Once I hit my sales target, I'll feel great.” But because success is a moving target – as soon as you hit your target, you raise it again, the happiness that results from success is fleeting. In fact, it works the other way around: People who cultivate a positive mind-set perform better in the face of challenge. I call this the "happiness advantage” – every business outcome shows improvement when the brain is positive. I've observed this effect in my role as a researcher and lecturer in 48 countries on the connection between employee happiness and success. And I'm not alone: In a meta-analysis of 225 academic studies, researchers Sonja Lyubomirsky, Laura King, and Ed Diener found strong evidence of directional causality between life satisfaction and successful business outcomes. Another common misconception is that our genetics, our environment, or a combination of the two determines how happy we are. To be sure, both factors have an impact. But one's general sense of well-being is surprisingly malleable. The habits you cultivate, the way you interact with coworkers, how you think about stress – all these can be managed to increase your happiness and your chances of success.