When and how perceived control buffers against cognitive declines: A moderated mediation analysis.

Although perceived control is a well-established predictor of cognitive aging, less is known about how and under what developmental circumstances these beliefs about personal influence may protect against cognitive declines. Our study examined light physical activity (LPA) as an unexplored mechanism that may link changes in two facets of perceived control (personal mastery, perceived constraints) to longitudinal trajectories of cognitive functioning. We also examined whether mediated pathways were moderated by age (i.e., differed across the adult lifespan). We analyzed two-wave, 9-year data from the national Midlife in the United States Study ( = 2,456; = 56 years, range = 30-84; 56% female) using autoregressive mediation and moderated mediation models. Mediation models showed that changes in personal mastery and perceived constraints predicted episodic memory and executive functioning via self-reported change in LPA. Only the mediated effects of constraints remained significant in a model that included both mastery and constraints as predictors. Moderated mediation models showed that, for episodic memory, the mediated pathways were strongest in old age and emerged only for constraints: For older but not younger adults, declines in constraints were associated with less decline in episodic memory, as mediated by increases in LPA. Results were consistent in sensitivity analyses that controlled for levels and change in moderate-to-vigorous physical activity. Findings inform lifespan theories of control and provide initial evidence that change in a largely overlooked health behavior (LPA) may underlie the link between perceived constraints and cognitive functioning, with this pathway becoming more pronounced in late life. (PsycInfo Database Record (c) 2025 APA, all rights reserved).