In the affect-regulation framework (Troy et al., 2023), affect-regulation methods are elicited by an adversity, leading individuals either towards or away from resilience. Stress is a powerful trigger of regulation methods and past research reveals substantive correlations between stress and rumination, which is a response type involving repetitive thoughts about the stress-inducing stimulus and its causes or consequences. Importantly, both are implied in the pathogenesis of several somatic and psychiatric health conditions.The causal direction between stress and rumination remains unclear, partly due to methodological issues concerning study design or choice of statistical analysis. This study aims to gather less biased insights by utilizing previously suggested solutions. It employs a stress task that incorporates both physiological and socio-evaluative components that have been shown to most effectively elicit a stress response and induce rumination. Most experimental studies in this field rely on artificially inducing rumination after the stressor, which introduces bias to the observed effect. Here, participants undergo a waiting period immediately after the stress task, during which they are free to think and feel. State rumination is evaluated only afterwards.This study models physiological data (cortisol and heart rate variability) in a mixed-effects growth curve framework with landmark registration in order to more accurately capture the stress response than traditionally applied mixed ANOVA.This is still an ongoing study. Results will be available in May and be included in the final poster. Preliminary results indicate that the stress task effectively induces rumination which in turn prolongs the physiological stress response.