I was intrigued to read (in the question "What positive writing exercises improve happiness?") the idea of a gratitude diary suggested as an intervention that "causes psychological well-being levels to increase in a lasting way".
Empirical studies suggest that people who use gratitude journals feel better about their lives and report fewer symptoms of illness. (Emmons & McCullough, 2003; Doverspike; Emmons Lab.)
However, there's also lots of dubious law of attraction-style writing on the topic, like this:
"Did you know that appreciation, gratitude and love are the highest forms of vibration? You can only have one vibration at a time, and if you are noticing what you appreciate and noticing what you are grateful for, you can't be noticing what you don't like."
And although studies find gratitude journals to be beneficial, they disagree on the most beneficial ways to keep one. Psychologist William Doverspike says:
"A daily gratitude intervention (self-guided exercises) resulted in more positive effects tha[n] did the weekly intervention."
But Jason Marsh of the Greater Good Science Center at the University of California, Berkeley says:
"Writing occasionally (once or twice per week) is more beneficial than daily journaling. In fact, one study by psychologist Sonja Lyubomirsky and her colleagues found that people who wrote in their gratitude journals once a week for six weeks reported boosts in happiness afterward; people who wrote three times per week didn’t."
So: which is likely to be correct in practice? And what best practices for keeping a gratitude journal can be inferred from other research, either specifically about gratitude or more generally in the cognitive sciences?
References:
- Doverspike, Ph.D., William F. "Gratitude: A Key to Happiness". Georgia Psychological Association.
- Emmons, R. A. & McCullough, M. E. (2003). Counting blessings versus burdens: An experimental investigation of gratitude and subjective well-being in daily life. Journal of Personality and Social Psychology, 84, 377-389.
- "Gratitude and Well-Being". Emmons Lab at the University of California, Davis.
Update (9th Dec 2013): I'm continuing to research this question. This article, while not terribly scientific, has some good jumping off points (infographic and links) that may help potential answerers!