Project Summary Alzheimer’s disease is prevalent at the end of life and remains the only leading cause of death without a cure or way to stop or significantly slow its progression. Prevention remains the best hope for reducing risk of Alzheimer’s disease in older adulthood. Given that Alzheimer’s disease has a complex etiology, with risk factors that range from genetics to the environment, multipronged approaches to prevention will likely be needed for an intervention to be broadly effective. Among the psychosocial risk factors for Alzheimer’s disease, personality traits have emerged as consistent predictors of cognitive health across adulthood. Specifically, higher neuroticism (the tendency to experience negative emotions and vulnerability to stress) and lower conscientiousness (the tendency to be organized, disciplined, and responsible) are associated with worse performance on cognitive tasks, more subjective cognitive complaints, and greater risk of Alzheimer’s disease and related dementias. Even after diagnosis, these traits are associated with behavioral and psychological symptoms at the end of life. Lifespan models of personality and health indicate that personality contributes to long-term health outcomes through both behavioral and clinical pathways. Missing from these models, however, are the antecedents of personality, novel mechanisms that go beyond behavioral and clinical risk factors, and how informant ratings of personality and cognition provide unique information about the target’s cognitive health. This work builds on the success of our previous award that found that personality is shaped by socioeconomic factors and that personality is one mechanism in the pathway from childhood socioeconomic status to adult cognitive health. The purpose of this project is to expand consideration of advantages and disadvantages experienced across the lifespan to include other domains, including structural and environmental advantages and disadvantages, to better understand how the accumulation and interplay of such factors across childhood and adulthood shape adult personality traits. This project will further evaluate socioemotional health and behavioral life skills as novel pathways from personality to cognitive health, which are hypothesized to be mechanisms that go beyond traditional behavioral and clinical risk factors. Finally, this project will also include informant ratings of personality and cognition as an additional source of information that provides unique information about the target’s health. We will address these aims in an ongoing longitudinal cohort study with a racially and socioeconomically diverse sample. The ultimate goal of this work is to develop a personality-informed intervention to support healthier cognitive aging and reduce risk of Alzheimer’s disease. We seek to build a robust and replicable evidence base for a lifespan model of personality and cognitive health that includes antecedents of personality and mechanisms ...