It is SMART to be HAPPY
"In fact, happiness is the single greatest competitive advantage in the modern economy. Only 25% of your job successes are predicted based upon intelligence and technical skills, though we spend most of our education and most companies hire based upon this category. The "silent 75%" of long-term job success is based upon your ability to positively adapt to the world: optimism, social support creation, and viewing stress as a challenge instead of as a threat."
Adapted from the quote by Shawn Achor [HBR], the author of "The Happiness Advantage"