Stress and the biology of inequality.

It is well established that health depends on socioeconomic circumstances, but the biology of this relation is not well described. Psychosocial factors operating throughout the life course, beginning in early life, influence a variety of biological variables. Research with non-human primates shows the effects of dominance hierarchy on biology, and similar metabolic differentials are evident in a hierarchy of white collar civil servants. The neuroendocrine "fight or flight" response produces physiological and metabolic alterations which parallel those observed with lower socioeconomic status. The biological effects of the psychosocial environment could explain health inequalities between relatively affluent groups.