Psychologist Walter Mischel explains how one little test involving a marshmallow might tell you a frightening amount about what kind of person you are. And Radiolab favorite Jonah Lehrer helps us make sense of the results. This one's all about our will power (or lack thereof).
Correction: An earlier version of this piece incorrectly stated that the kids who performed better on the marshmallow test had higher GPAs in high school and went to better colleges. Those elements were not a part of Mischel’s original study. The audio has been adjusted to reflect this fact.