Mindfulness is associated with a wide range of beneficial outcomes such as well-being. However, less is known about the mechanisms underlying these benefits. Some researchers suggest that the benefits could be driven by emotion regulation, either by improving the effectiveness of emotion regulation or by lessening the need for effortful emotion regulation. By using two longitudinal Ambulatory Assessment data sets (NStudy1 = 125, NStudy2 = 175), based on a six-week randomised controlled trial and a one-week study, we tested these competing notions in daily life and found support for the latter: Mindfulness, and especially its non-judgmental acceptance facet, was significantly associated with less use of emotion regulation strategies. However, mindfulness was not significantly associated with more effective emotion regulation strategy implementation. Moreover, the mindfulness training focusing on present-moment attention and awareness did not significantly influence emotion regulation. These findings demonstrate the importance of the non-judgmental acceptance component for emotion regulation and affective well-being.
Keywords: Mindfulness; ambulatory assessment; emotion regulation; emotion regulation strategies; reappraisal.