25. In a study on the attitude of gratitude, 192 undergraduates were assigned randomly to one of three clusters and asked to keep a regular report on psychological and physical indicators. One cluster was given a prompt to list things in their lives they are grateful for, another cluster’s prompt was to list recent hassles, and the third cluster’s prompt was to simply list events that recently had an impact on them. The “gratitude group” generally reported higher well-being. [R. A. Emmons and M. E. McCullough, Counting blessings versus burdens, Journal of Personality and Social Psychology 84(2) (2003):377–389.]