Leaving a high-flying job in consulting, Angela Lee Duckworth took a job teaching math to seventh graders in a New York public school. She quickly realized that IQ wasn't the only thing separating the successful students from those who struggled. Here, she explains her theory of "grit" as a predictor of success.

"Do what you love" is often terrible advice. Instead of taking the job that will make you happiest, look for the one where you'll learn the most. (Audio only)