Like clouds in a windy sky: Mindfulness training reduces negative affect reactivity in daily life in a randomized controlled trial.

While prior research has found mindfulness to be linked with emotional responses to events, less is known about this effect in a non-clinical sample. Even less is known regarding the mechanisms of the underlying processes: It is unclear whether participants who exhibit increased acceptance show decreased emotional reactivity (i.e., lower affective responses towards events overall) or a speedier emotional recovery (i.e., subsequent decrease in negative affect) due to adopting an accepting stance. To address these questions, we re-analysed two Ambulatory Assessment data sets. The first (N_Study1 = 125) was a 6-week randomized controlled trial (including a 40-day ambulatory assessment); the second (N_Study2 = 175) was a 1-week ambulatory assessment study. We found state mindfulness to be more strongly associated with emotional reactivity than with recovery, and that only emotional reactivity was significantly dampened by mindfulness training. Regarding the different facets of mindfulness, we found that the strongest predictor of both emotional reactivity and recovery was non-judgemental acceptance. Finally, we found that being aware of one's own thoughts and behaviour could be beneficial or detrimental for emotional recovery, depending on whether participants accepted their thoughts and emotions. Together, these findings provide evidence for predictions derived from the monitoring and acceptance theory.