Why do feelings persist over time in daily life? Investigating the role of emotion-regulation strategies in the process underlying emotional inertia.

Emotions do not simply turn on and off again in an instant; rather, emotions rise and fall gradually, often persisting for a considerable period. Although it is normative for emotions to show a degree of momentum-a phenomenon known as emotional inertia-the tendency for emotions to be overly persistent has been associated with psychological maladjustment. However, the mechanisms underlying emotional inertia remain unclear. We aimed to fill this gap in the present study by investigating how the persistence of affect over time (emotional inertia) is mediated-at the within-person level-by the use of emotion-regulation strategies in daily life. We ran secondary analyses on eight experience sampling data sets collected between 2009 and 2021 (total N = 948 participants measured at 73,472 occasions), in which participants reported their momentary experiences of positive affect and negative affect and their recent use of four emotion-regulation strategies (distraction, cognitive reappraisal, rumination, and expressive suppression). We used dynamic structural equation modeling to estimate indirect effects of each strategy on the inertia of positive affect and negative affect. All four strategies reliably mediated both negative affect inertia and (to a lesser extent) positive affect inertia, supporting the notion that the use of emotion-regulation strategies represents a mechanism underpinning emotional inertia, at least among highly educated, nonclinical, Australian and Belgian young adults. However, each regulation strategy reduced the total autoregressive slope of affect at t-1 predicting affect at t by no more than 13%, suggesting factors other than emotion-regulation strategies also play important roles in emotional inertia. (PsycInfo Database Record (c) 2025 APA, all rights reserved).