A coordinated analysis of the associations among personality traits, cognitive decline, and dementia in older adulthood

•Low neuroticism and high openness were associated with high cognitive function.•Openness was associated with steeper cognitive decline after dementia diagnosis.•Models were coordinated and harmonized across 4 independent longitudinal studies. There are individual differences in the rates of cognitive decline across later adulthood. Personality traits are among the factors that may account for these differences. The current project investigated whether personality traits were associated with trajectories of cognitive decline, and whether the associations were different before and after dementia diagnosis. The data was analyzed using linear mixed effects regression. Across study aims is a focus on replicability and generalizability. Each question was addressed in four independent longitudinal studies (EAS, MAP, ROS, SATSA), then meta-analyzed, providing estimates of replicability. Results indicated that low neuroticism and high openness were associated with total cognitive function. We detected evidence for cognitive decline in all four samples, and openness was associated with decline post dementia diagnosis.