Possible link between poverty and health

About a year ago I went on a field trip to the California Science Center to dissect cow eyes with a class of third graders. I am a mentor for a 3rd grade student through an organization called I Have a Dream (IHAD). I was awestruck by how smart, funny, adorable, and happy these children were. They live in Inglewood, and there is not one Caucasian student in their class. They are from very low SES families. During lunch I was sitting at a picnic table chatting with three giggling girls. We started talking about pets. One girl told us that a few weeks ago she woke up and went to the kitchen to get some juice and found her dog’s head on the floor. A criminal had come into the house in the middle of the night, stolen a few things, and decapitated her dog with a chain. Probably noticing how shocked I was by the story, several other girls chimed in with their own stories, about murders and rapists living on their street. This was their life. This was their reality.
My experience with these 3rd graders links directly to an article on the impact of early-life social environments on health in adulthood. Gregory Miller’s article “Health Psychology: Developing Biologically Plausible Models Linking the Social World and Physical Health” discusses stress as a pathway for linking psychosocial factors to health outcomes. People raised in low SES neighborhoods have been found to experience great numbers of stressful life events. Seeing your dog decapitated at age 9 definitely goes into the stressful life events category. The author points out that a theory is needed to explain how negative life events (external stimuli) might have biological effects on the individual level. His model proposes that because children from low-SES neighborhoods experience more negative unpredictable events, these children develop a lowered threshold for perceived threat in new situations. The theory argues that in social situations that are ambiguous, low SES children will interpret these situations in a more threatening manner then high SES children. This threat perception will then affect biological responses to stress.  Thus, throughout life as these individuals encounter and perceive more situations that are threatening, their exaggerated and overworked stress response systems may be burnt out and unable to fend off disease. This is one explanation for why low SES adults have increased incidences of disease even after accounting for lack of access to healthcare.