This chapter examines the impact of violence and trauma on young children's development through an environmental lens, beginning with the child's internal psychophysiological environment. It considers the ways in which children's physiologies are regulated by the relationships that guide their growth and dysregulated by trauma. The chapter demonstrates that parallel processes occur in the child's caregiving environment as caregivers and family are regulated and strengthened by social and cultural environments that nurture them and dysregulated when those environments are neglectful and dangerous. It shows that parents' own response to violence in their environments changes the way they think about and behave toward their children, shaping their children's development in ways that can persist into the next generation. Efforts to help children must target not only child behaviors and symptoms but the caregiving environments that sustain children and shape the trajectories of their development.