A UPenn psychologist explains why 'follow your passion' can give the wrong impression about success

If there's one common refrain throughout college commencement speeches, it's this: "Follow your passion."

That advice can be truly inspiring for grads who already have a passion - say, medicine or law or mechanical engineering. But it can be equally distressing for those who sort of like art, and sort of like math, and sort of like foreign languages, and are sort of freaking out about having to choose.

Angela Duckworth, a professor of psychology at the University of Pennsylvania, would have that second group of grads take the speaker's advice with a grain of salt.

"That advice leaves something out of the question," she told Business Insider, "which is, 'What is my passion and how do I follow something when I don't even know what it is?'"

What the speakers typically fail to mention, she said, is that "passions begin with interest and interests are not merely discovered; they're also actively developed and deepened."

In other words, a "passion" isn't simply hiding out like an Easter egg buried in the backyard, just waiting for you to unearth it. Instead, passions are often created over time, through a series of experiences.

Duckworth's new book, "Grit," includes multiple examples of people who engaged in precisely this passion-creating process. For instance, she notes how the movie "Julie & Julia" shows a young Julia Child taking a bite of sole meuniere (a fish dish) and falling in love.

As Duckworth writes, "that ethereal morsel of sole meuniere was indeed a revelation. But her epiphany was that classical French cuisine was divine, not that she would become a chef, cookbook author, and, eventually, the woman who would teach America to make coq au vin in their very own kitchens."

When Duckworth read through Child's autobiography, she realized that the French meal was followed by a series of "interest-stimulating experiences," including meals in Paris bistros, reading through French cookbooks, and hours of cooking classes.

All these experiences combined led to Child's passion for French cooking.

"The crucial thing to know about [interest development]," Duckworth told us, "is that it takes time, it takes effort, and it takes support from other people."

So there's hope for all those college grads who worry that they'll never be successful because they don't yet have a clear sense of their passion. But there's also work for them to do - get out there and experiment with different jobs and career fields. Your life is yours to create.