This project will conduct secondary analysis of data from The Heart of Detroit Study (THDS) to examine the unique contributions of discrimination and general stress to naturalistic change in negative and positive affect during the daily lives of urban African American adults. Specifically, dynamic structural equation models will analyze ecological momentary assessment data to evaluate reactivity of (i.e., change in) momentary positive and negative affect in response to within day reports of general stress and discrimination. Planned follow-up analyzes will evaluate between-person heterogeneity in reactivity of positive and negative affect to both general stress and discrimination including the potential association of elevated reactivity with baseline assessment of neuroticism and depressive syndrome severity. The analyses relevant to the hypotheses proposed in this pre-registration have not been performed.