Thankful or Thank You? Exploring the Impact of Intrapersonal and Interpersonal Gratitude

Gratitude has been found to have many positive benefits, whether it is introspective or interpersonal in nature. This research explored the differential effects of an interpersonal and intrapersonal gratitude intervention on subjective well-being (SWB). Participants were assigned to one of three intervention conditions that were characterized by a weekly writing task—an interpersonal gratitude letter (n = 73), an intrapersonal gratitude journal (n = 65), or a learning journal (n = 67), which served as the control. A four-week, repeated gratitude intervention design was conducted, wherein participants' SWB was assessed across 12-time points, including a pre- and post-intervention SWB battery to assess the intervention’s overall impact. Participants in both gratitude conditions reported an overall increase in positive affect, supported by text analysis. However, participants who wrote gratitude letters had significantly less negative affect compared to the gratitude journal participants. Further analysis revealed a significant difference in SBW between the two gratitude conditions. Specifically, participants who experienced the intrapersonal gratitude journal-writing task reported a significant improvement in life satisfaction, while participants in the interpersonal gratitude letter-writing task evidenced a significant improvement in perceived social support. The control condition unexpectedly exhibited an increase in SWB that was likely due to the salience of the participants’ scholastic accomplishments. Finally, individual differences, including The Big Five, predicted gratitude and positive affect, consistent with prior research.