There is a growing recognition that thoughts often arise independently of external demands. These thoughts can span from reminiscing your last vacation to contemplating career goals to fantasizing about meeting your favorite musician. Often referred to as mind wandering, such frequently occurring unprompted thoughts have widespread impact on our daily functions, with the dominant narrative converging on a negative relationship between unprompted thought and affective well-being. In this systematic review of 76 studies, we implemented a meta-analysis and qualitative review to elucidate if and when unprompted thought is indeed negatively associated with affective well-being in adults. Using a multilevel mixed-model approach on 386 effect sizes from 23,168 participants across 64 studies, our meta-analyses indicated an overall relationship between unprompted thought and worse affective well-being (r = −.18, 95% CI [−.23, −.14]); however, the magnitude and direction of this relationship changed when considering specific aspects of the phenomenon (including thought content and intentionality) and methodological approaches (including questionnaires vs. experience sampling). The qualitative review further contextualizes this relationship by revealing the nuances of how and when unprompted thought is associated with affective well-being. Taken together, our metaanalysis and qualitative review indicate that the commonly reported relationship between unprompted thought and affective well-being is contingent upon the content and conceptualization of unprompted thought, as well as the methodological and analytic approaches implemented. Based on these findings, we propose emerging directions for future empirical and theoretical work that highlight the importance of accounting for when, how, and for whom unprompted thought is associated with affective well-being.
Public Significance StatementA large portion of our mental content is "unprompted" by nature such that it is unrelated to the ongoing task or our physical surroundings. Our meta-analytic review provides a comprehensive overview of how unprompted thought relates to how we feel, revealing that unprompted thoughts are generally associated with reduced affective well-being. Notably, this relationship was mitigated and at times reversed depending on the content of unprompted thought as well as how it was defined and measured. We found that unprompted thoughts were associated with worse affective well-being only when thoughts were unintentional, ruminative, and contain negative content. In fact, this relationship was not reliable when time-sensitive measures were used, and it even turned positive during future-oriented, positive, or freely moving thoughts. Taken together, we found that the type and content of unprompted thought can determine whether it is linked to our happiness.