For more than 100 years, academic economists have treated the market almost like a force of nature--a vast invisible system that operates independently from human emotions. But on a day-to-day basis, emotion plays a big role in the choices we make. In this podcast, we talked to Jennifer Lerner, a social psychologist at Harvard University, about how our feelings affect our financial decisions. Podcast produced by David Levin. Original interview by Malcolm Clark. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by ExxonMobill, David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and public television viewers. Additional funding for "Mind Over Money" provided by T. Rowe Price. To learn more about what caused the economic crash of 2008, go to pbs.org/nova/money