Over the course of the lifespan, humans encounter and must adapt to various psychosocial and physiological challenges. During childhood, we experience critical periods during which we are particularly sensitive to stimuli in our environment and received care from primary caretakers. Experiences of persistent stress or trauma during childhood can have deleterious effects on mental health and physical growth and development. Children who experience particularly challenging stressors including poverty, abuse, neglect, or exposure to violence face higher risk of delayed or diminished growth, obesity, mental health challenges including anxiety, depression and post‐traumatic stress syndrome (PTSD), and chronic disease in adulthood. Current research investigates ways to mediate this risk via social support for primary caregivers and improvements in social conditions that may have transgenerational effects.