This research tested the hypothesis that mindful-gratitude practice attenuates the robust association between collective narcissism and prejudice. In Study 1 (a between-subjects study using a nationally representative sample of 569 Polish adults; 313 female), 10 min of mindful-gratitude practice-compared to mindful-attention practice and control-did not decrease prejudice (anti-Semitism), but weakened the positive link between collective narcissism and prejudice. In Study 2 (a preregistered, randomized, controlled-trial study using a convenience sample of 219 Polish adults; 168 female), a 6-week mobile app supported training in daily mindful-gratitude practice decreased prejudice (anti-Semitism, sexism, homophobia, anti-immigrant sentiment) and its link with collective narcissism compared to a wait-list control. The hypothesis-consistent results emphasize the social relevance of mindful-gratitude practice, a time- and cost-effective intervention.
Keywords: anti-Semitism; anti-immigrant sentiment; collective narcissism; gratitude; homophobia; mindfulness; open data; open materials; prejudice; preregistered; sexism.