The way people age varies significantly from one individual to another. This variation is attributed to a combination of factors, including genetics, environment, psychological and social factors, and lifestyle choices. Individuals from lower socioeconomic groups often experience faster physical and mental aging, contributing to a growing health divide and increasing health inequities. Socioeconomic conditions affect not only the rate at which health deteriorates but also the highest level of health a person can achieve, starting from conception. The specific mechanisms of this impact, particularly in early life and in older age, require further research. This research program will analyze data from population cohorts of different ages to understand the influence of social and economic environments on developmental and aging trajectories from early life to old age. It aims to identify factors that might protect individuals from the adverse effects of lower socioeconomic conditions on health and aging. This knowledge will assist in shaping and implementing targeted health policies to improve the health and aging trajectories of the population, thereby reducing health inequities and lessening the burden on the health system.