Emotion, Vol 26(3), Apr 2026, 567-580; doi:10.1037/emo0001598
Repeated assessments in everyday life allow for ecologically valid data on dynamic, within-person stress processes. However, typical designs offer little information on the immediate shape of affective responses following daily stressors, including the influence of situational and person-level variables. In a combined clinical and community sample (N = 248; recruited between 2016 and 2018), we employed a high-density intensive-longitudinal protocol (observations N = 1,442) to capture the temporal dynamics of affect in response to daily stressful events using a microburst design. Specifically, we implemented an adaptive signal-contingent schedule, where an initial stressor report triggered an intense burst of prompts in 15-min increments over the course of 1 hr inquiring about momentary affect. To model affective microtrajectories, we used multilevel structural equation modeling. A piecewise linear growth model consistently showed the best fit across all indices for both negative and positive affect. Affective responses to momentarily experienced stressors were best captured by a model that allowed for changes in affect trajectories over time (an initial steep decline/increase followed by gradual change), with more stressful situations amplifying these trajectories. Moreover, extraversion significantly influenced the initial rise in positive affect, leading to more pronounced early changes in those with higher levels of extraversion. In contrast, neuroticism had an opposite effect on positive affect, dampening these early changes. Results offer a detailed understanding of daily stress dynamics by providing insights into the immediate and evolving nature of affective responses to stress, with implications for personalized stress management strategies. (PsycInfo Database Record (c) 2026 APA, all rights reserved)