What motivates us to work? Contrary to conventional wisdom, it isn’t just money. But it’s not exactly joy either. It seems that most of us thrive by making constant progress and feeling a sense of purpose. Behavioral economist Dan Ariely presents two eye-opening experiments that reveal our unexpected and nuanced attitudes toward meaning in our work. (Filmed at TEDxRiodelaPlata.)

Why you should listen to him:

Despite our best efforts, bad or inexplicable decisions are as inevitable as death and taxes and the grocery store running out of your favorite flavor of ice cream. They’re also just as predictable. Why, for instance, are we convinced that “sizing up” at our favorite burger joint is a good idea, even when we’re not that hungry? Why are our phone lists cluttered with numbers we never call? Dan Ariely, behavioral economist, has based his career on figuring out the answers to these questions, and in his bestselling book Predictably Irrational (re-released in expanded form in May 2009), he describes many unorthodox and often downright odd experiments used in the quest to answer this question.

Ariely has long been fascinated with how emotional states, moral codes and peer pressure affect our ability to make rational and often extremely important decisions in our daily lives — across a spectrum of our interests, from economic choices (how should I invest?) to personal (who should I marry?). At Duke, he’s aligned with three departments (business, economics and cognitive neuroscience); he’s also a visiting professor in MIT’s Program in Media Arts and Sciences and a founding member of the Center for Advanced Hindsight. His hope that studying and understanding the decision-making process can help people lead better, more sensible daily lives.

He produces a weekly podcast, Arming the Donkeys, featuring chats with researchers in the social and natural sciences.

“If you want to know why you always buy a bigger television than you intended, or why you think it’s perfectly fine to spend a few dollars on a cup of coffee at Starbucks, or why people feel better after taking a 50-cent aspirin but continue to complain of a throbbing skull when they’re told the pill they took just cost one penny, Ariely has the answer.”

Daniel Gross, Newsweek