Agency is a relational developmental construct. The most basic form of agency is already present in the dynamic, self‐organizing activities of living systems. We discuss how, from the earliest point in the development of persons, agency manifests in different forms and grows through the interrelations of various bio‐psycho‐social processes. These processes can be organized into general levels, including the levels of biophysical agency, psychosocial agency, and sociocultural agency. We further describe how the most flexible and richest forms of agency seen in adulthood build from developmental processes evidenced throughout the life span: infants’ sensorimotor and perceptual functioning, toddlers’ symbolic representational and linguistic functioning, the child's self‐regulatory functioning, and adolescents’ and young adults’ moral functioning. Altogether these functions provide persons with the ability to create the conditions for their own agency, particularly through their participation in community life. This chapter ends with a discussion of the role that civic institutions, especially higher education, must play in expanding human agency.