Debating what makes a worker truly happy has long kept happy hour revelers occupied (and crying in their beers). There's a barometer for that debate -- so you can invoke science to prove your point. But if you look at the pillars of well-being according to researchers -- "environment," "appreciation," and "emotion" -- a global definition of workplace mental health and satisfaction seems rather unscientific. Well-being, it turns out, is a matter of perception.

The World Economic Forum, reporting on the annual Edenred-Ipsos Barometer, concluded that on average, 71% of employees (out of more than 14,000 surveyed in 15 different countries) report feeling positive about their work. Also on average, those employees are more satisfied with their work environments (covering equipment, expectations, reliability of colleagues, and a sense of work/life balance) and less happy with appreciation (feeling respected by employers, for instance) and emotion (enjoy coming to work, for instance). When you combine environment, appreciation, and emotion, some of the nuances fall away-such as Japanese workers who clearly understand what's expected of them, but struggle to enjoy their jobs, or Belgian, French, and German workers who enjoy work/life balance, but feel underappreciated by their employers.

Why does all this matter? In one way, it doesn't -- from the proletariat to the Dilbertesque office drones of the world, workers will always find ways to gripe. In another way, workplace happiness characterized by three (or even three dozen) pillars is critical to a company's success. Happy workers "go the extra mile" -- or, if they simply go the requisite mile, they do so with a generally positive outlook.