Meta-analysis of the association between gratitude and loneliness.

Gratitude is a positive social emotion that involves recognizing that others have brought benefits into one's life. Loneliness, on the other hand, is an unpleasant emotion resulting from a perceived lack of social connectedness. Although previous studies have reported an inverse association between gratitude and loneliness, these studies have not been systematically examined in a single review. To address this gap in the literature, we conducted a random-effects meta-analysis to examine the association between gratitude and loneliness. Analysis of 26 studies revealed a moderate sized effect (mean Fisher's z transformed correlation, z_r = -.406, 95% confidence interval [CI] = -.463, -.349; mean back-transformed correlation, r = -.385, 95% CI = -.433, -.335). To complement these effect sizes, we calculated a probability-based common language effect size for correlations. Random-effects homogeneity testing suggested the presence of effect size heterogeneity. Analyses of both continuous and categorical moderators were non-significant, indicating that these variables did not influence effect size magnitude. Furthermore, publication bias tests suggested that our results were not influenced by unpublished studies. Finally, we proposed several statistical and clinical recommendations for future research. Regarding the latter, we offered suggestions for modifying gratitude enhancement programs with the aim of reducing loneliness.