Thomas Lu

Why do you work? Popular wisdom says your answer depends on what your job is.

But psychologist Amy Wrzesniewski at Yale University finds it may have more to do with how we think about our work.

Paul Rozin has been studying the psychology and culture of food for more than 40 years. And he's come to appreciate that food fills many of our needs, but hunger is just one.

"Food is not just nutrition that goes in your mouth or even pleasant sensations that go with it," he says. "It connects to your whole life, and it's really a very important part of performing your culture and experiencing your culture."