This chapter explores how the emergence of small, kin-based foraging bands shaped the cognitive and social foundations of human cooperation, altruism, and religious interpretation. It examines how evolutionary pressures favored extended families, whose survival depended on reciprocity, reputation, and the careful regulation of social harmony. Drawing on ethnographic and evolutionary evidence, it explains how such groups fostered kin-selected altruism and cultural reproduction through shared knowledge and caregiving networks. The chapter then traces the origins of shamanism as an early institutional response to uncertainty—ritual specialists interpreting and negotiating with spiritual agents to maintain group cohesion and meaning. From trance ceremonies and psychoactive experiences to the cognitive habit of attributing agency to natural phenomena, the shamanic role illustrates how religious thought evolved from adaptive group processes. Ultimately, these early dynamics reveal enduring predispositions that continue to shape modern human cooperation and belief systems.