A critical test of emotion regulation strategy effectiveness in daily life: Individual differences and situational contexts.

= 161,513 measurement occasions) examining strategy effectiveness in daily life. Acceptance, reappraisal, and social sharing were, on average, associated with more favorable subsequent affect, whereas rumination, suppression, and, to a lesser extent, distraction were not. Yet there was substantial between-person variability in the effectiveness of every strategy, indicating that strategies considered effective on average were ineffective or even counterproductive for a meaningful subset of individuals. Most strikingly, approximately 75%-80% of the variance in effectiveness was explained by the intensity of the affective state individuals were attempting to regulate, suggesting that observed effectiveness largely reflects situational difficulty rather than intrinsic properties of strategies. A complementary analysis of a novel measure of negative affect pile-up further revealed a shift from greater reliance on putatively adaptive strategies during brief spikes in negative affect to greater reliance on putatively maladaptive strategies as elevated negative affect persisted. Together, these findings challenge the prevailing focus on short-term, strategy-level effectiveness in everyday life and highlight the need for emotion regulation assessments that better capture person-strategy-situation fit and the temporal dynamics of emotional episodes. (PsycInfo Database Record (c) 2026 APA, all rights reserved).