Background — No study has experimentally examined the effects of mindfulness on anger rumination. While Anderson et al. (2007) reported that mindfulness-based intervention decreased anger rumination, its mechanism was unclear. Anger rumination is defined as a tendency to engage in unintentional recurring thoughts about anger episodes in the past (Sukhodolsky, Golub, & Cromwell, 2001). To alleviate its negative effects on anger, it might be important to accept the thoughts without judging (Wright et al., 2009) or suppressing them. Mindfulness might help in accepting the thoughts, and thus reducing the frequency of anger-related thoughts.
Aims — To examine whether mindfulness reduced the frequency of anger-related thoughts more than other emotion regulation strategies like distraction.
Methods — Japanese undergraduates (N = 67, M age = 19.46 years, SD age = 1.17 years, range = 18 – 22 years; 76.1% female) participated in the study. Before the experiment, anger rumination was assessed using Anger Rumination Scale (ARS; Sukhodolsky et al., 2001). Participants engaged in 2 tasks: (a) free recall (2 min) and (b) emotion regulation strategy (5 min). In free recall, participants freely recalled a memory involving anger, and then reported the intensity of their current feeling of anger. Immediately after this, task (b) began, where participants were instructed to record anger-related thoughts when they occurred. Moreover, participants were randomly assigned to 3 conditions: mindfulness, distraction, and control. The project was approved by The Ethics Board of Psychological Research of Kansai University. All participants provided informed consent.
Results — A 2 (high and low anger rumination condition) × 3 (mindfulness, distraction, and control Condition) ANOVA on frequency of anger-related thoughts indicated that the Group × Condition interaction was significant, F (2, 47) = 9.02, p < .001, ηp2 = .28. A simple main effect test showed that participants assigned to control condition had anger-related thoughts more than mindfulness (p = .002) and distraction (p < .001) in high anger rumination group.