Most of the time, optimism and confidence are described as keys to success in one's career, but it may not be that simple. Psychologist Julie Norem, a professor at Wellesley College, has done intensive research on the idea of defensive pessimism and is the author of "The Positive Power of Negative Thinking." She talks with Tim Muma about the important role of pessimism and how some people need to hear something different to thrive in their careers.