The World Health Organization published a report on 28 August 2008 that showed how social factors influence health and life expectency around the world. The report is based on a three year study by the WHO Commission on the Social Determinants of Health, chaired by Sir Michael Marmot.

For example, the research shows that “a girl in the African country of Lesotho is, on average, likely to live 42 years less than a girl in Japan.”

For more on this study, see the full report or read the executive summary.