The impacts of toxic stress manifest themselves across several physiological dimensions, none more important than in neurological development. Exposure to sources of toxic stress leads to the elevation of neuro-endocrineimmune responses resulting in prolonged cortisol activation and a persistent inflammatory state, with failure of the body to normalize these changes after the stressor is removed. It is the failure of these elevated levels to recede normally – given the persistent presence of these threats – that directly impact the neurological architecture of a child’s brain.

Brains are wired in the first years after birth, and brain scans of children living in poverty reveal the extent of this disparity in neural development. By two years of age, obvious gaps in the neurological fabric of children have already developed as a consequence of the physiological impacts of being exposed to sources of toxic stress. This is highly consequential considering most of the resources and formal interventions dedicated to preparing children for school don’t start until a child is four years of age. The science suggests that this is four years too late.

Research demonstrates how neighborhood quality influences health across a variety of dimensions including infant mortality, life expectancy and chronic disease. Residency in distressed neighborhood, for example, is “a strong, independent predictor of diabetes.” Similarly, being raised in a distressed neighborhood will increase a child chance of developing a mental illness.

The information for this Lesson Learned is included in POVERTY AND PLACE: A Review of the Science and Research That Have Impacted Our Work, a white paper that offers an overview of selected research that has informed our thinking as we continue to fight against intergenerational urban poverty.