Capturing wear in wear and tear: The negative-affect reactivity linked to discrimination is associated with biological age across two national samples of adults in the United States.

OBJECTIVE: Chronic psychological stress responses to discrimination may be associated with more accelerated paces of biological aging at a particular window of time through epigenetic changes in DNA methylation, including in third-generation epigenetic clocks (i.e., the DunedinPACE and GrimAge2). Although discrimination is often measured by frequency, fewer studies examine how its cumulative psychological toll is associated with biological age acceleration, which is a theoretical proposition aligned with the weathering hypothesis. METHODS: The present study analyzed data from two national longitudinal studies: 397 adults completing eight daily diaries in the Midlife in the United States study and 2,059 adults completing five biennial surveys in the Health and Retirement Study. We modeled the within-person associations (i.e., slopes) between discrimination and negative affect as correlates of biological aging captured by the DunedinPACE and GrimAge2 clocks. RESULTS: Across both studies, adults who experienced more discrimination, on average, reported more negative affect. Stronger positive slopes between discrimination and negative affect were associated with faster paces of biological aging at the time of assessment in only the DunedinPACE clock in the Midlife in the United States study and in the DunedinPACE and GrimAge2 clocks in the Health and Retirement Study. These associations persisted after adjusting for the frequency of discrimination, highlighting the importance of modeling stress reactivity rather than exposure alone. CONCLUSIONS: Findings support the weathering hypothesis, suggesting cumulative negative emotions linked to discrimination relate to accelerated biological aging. Future research could leverage longitudinal approaches to identify vulnerable populations and inform interventions to reduce the biological embedding of discrimination. (PsycInfo Database Record (c) 2026 APA, all rights reserved).