In two recent experiments, researchers found that participants who wrote and sent letters of gratitude experienced an increase in happiness and life satisfaction as well as a decrease in feelings of depression.
These studies are based on early research which found that writing which included more frequent positive words had positive effects on mood1. To expand upon these findings, a later experiment2 tested the effects of writing thank-you letters on 85 undergraduate psychology students.
The participants were all given psychological questionnaires to determine their initial levels of happiness, gratitude, and life satisfaction. Over the next 8 weeks, half of the participants were given instructions to write letters expressing gratitude every 2 weeks. They were instructed to write letters which “included something significant for which they felt gratitude toward the recipient” and to “be reflective, write expressively, and compose letters from a positive orientation.” At the end of the 8 weeks, all participants repeated the initial psychological questionnaires.
The results indicated that participants in the letter-writing group reported significantly increased subjective well-being, while the no-writing group reported no difference. Since the letter-writing was spread over 8 weeks, this study also shows that this exercise can be repeated at regular intervals to cause long term benefits to a person’s mood.
The experiment was later replicated with an expanded questionnaire and an increased sample size of 219 participants. The results showed that, in addition to the positive effects found in the first experiment, letter-writing can also decrease symptoms of depression3.
This post is part of our series on “happiness interventions,” or activities you can do that have been scientifically shown to increase happiness. Sign up for our mailing list to receive an email every week with a happiness activity.
1 Pennebaker, J. W., & Seagal, J. D. (1999). Forming a story: The health benefits of narrative. Journal of clinical psychology, 55(10), 1243-1254.
2 Toepfer, S. M., & Walker, K. (2009). Letters of gratitude: Improving well-being through expressive writing. Journal of Writing Research, 1(3), 181-198.
3 Toepfer, S. M., Cichy, K., & Peters, P. (2012). Letters of gratitude: Further evidence for author benefits. Journal of Happiness Studies, 13(1), 187-201.