Individual Differences in the Affective Experience of Writing a Gratitude Letter: Who Benefits Most?

This study merged archival data from three separate experiments to investigate the typology of individuals who benefit most and least from gratitude letter writing interventions (N = 487). First, k-means clustering of pre- to post-intervention changes in affect revealed three distinct groups: Buffered, Mixed Feelings, and Backfired. The Buffered cluster comprised individuals who, on average, experienced decreases in negative affect (e.g., less frustration) but no changes in positive emotions (e.g., joy). The Mixed Feelings cluster experienced increases in positive and self-conscious affect (e.g., indebtedness). The Backfired cluster experienced decreases in positive feelings and increases in negative affect. Next, differences in individual characteristics across clusters indicated that those in the Buffered cluster were relatively more neurotic, had higher baseline negative feelings, and had lower trait gratitude. Those in the Mixed Feelings cluster were comparatively more agreeable and seemed to put more effort into the activity. Finally, those in the Backfired cluster had relatively higher baseline positive feelings and were more open and conscientious. These findings contribute to understanding individual differences in the effectiveness of gratitude letter interventions and highlight opportunities to tailor such activities to promote personal growth.