To study the effect of the gratitude list, researchers have had to define gratitude and decide how to measure it. Some psychologists contend that gratitude has two emotional components: a “thank you” combined with a recognition that a benefit came from an outside source. This idea sits at the heart of the list’s place in 12-step programs. The list provides a daily structure to modify habits of thought over time, training participants to notice their positive accomplishments rather than dwelling on worries or resentments that might trigger self-destructive behavior.
Some studies suggest that a focus on gratitude improves the ability to assess life quality, the willingness to help others, and the quality of sleep and overall physical health. In a study among Israeli youth exposed to missile attacks, researchers go as far as proposing that gratitude increases resilience against PTSD. And in a quest to find a “gratitude mechanism,” the Greater Good Science Center at UC Berkeley funded a multiyear grant program in 2011, along with a gratitude summit in 2014. Researchers have also attempted to pin down a genetic component—a sort of gratitude gene that could play a role in oxytocin processing.
But gratitude long predates social-scientific study of the concept. Benjamin Franklin, influenced by the Puritans and Quakers of Boston, expressed the essence of this can-do mode of character reformation by publishing daily logs of productivity and virtue. His schedule for writing and working started at 5 a.m., with the question, “What good shall I do this day?”