dr. nadine burke harris. >> welcome. you work with kids who are repeatedly exposed to what you call toxic stress. give us a sense of the kids you work with in places like bay view hunters point and neighborhoods like that, what some kids who live in those places go through. what's life like? >> sure. what we see is many kids who are exposed to things like certainly a lot of community violence, but also kids who are growing up in families where there's a parent with mental illness or perhaps substance dependance. and some of the challenges that they see in determines of just dealing with household function. there's a lot of families where one parent isn't as home or maybe a parent is incarcerated. and so these are the challenges that we see. >> what's interesting and what you've discovered and what others have discovered and you're building on is the idea that this affects them not just psychologically but physio psychologically. talk about the physiological changes that happen. >> that's right. when kids are exposed to t