Allport proposed that personality develops through stages of selfhood from infancy to adulthood. The earliest stage is the bodily self in infancy, focused on physical sensations and needs. Next is the personal self of childhood, where a sense of identity separates from others. In adolescence and beyond, the social self emerges through relationships and roles. The final stage is the transpersonal self, oriented toward universal principles like justice that transcend individual concerns. Allport saw personality developing as an increasingly complex self-concept at the core of one's being.