Robert A. Emmons, Ph.D., professor of psychology at the University of California, Davis (http://psychology.ucdavis.edu/Emmons/), is the author of The Psychology of Ultimate Concerns: Motivation and Spirituality in Personality and numerous articles in peer-reviewed journals. With Joanna Hill, he is the author of Words of Gratitude for Mind, Body, and Soul (Templeton Foundation Press, 2001). His research is funded by the John Templeton Foundation.