“Mission: Joy” with Peggy Callahan and Elissa Epel

Centered on a friendship between the Dalai Lama and Archbishop Desmond Tutu, the documentary Mission: Joy was produced and co-directed by Peggy Callahan while its real life complement, The Big Joy Project, is an experiment in “citizen science.” She and Dr. Elissa Epel, vice chair of psychiatry at the University of California, San Francisco, talk about how both point the way to more joy in our everyday lives.