Whether we compare groups within a society, across national borders or over time, the findings are similar: health varies and reflects different social, economic and political realities. Not only are the social origins of health substantial and persistent, but they offer the greatest prospect for improvements in population health. Of course, health needs differ according to social and physical location, and health problems are variably responsive to prevailing social, cultural and political forces. Different social and physical environments variably lead to particular health outcomes. While we know a great deal about the impact of the social and physical environment on health, much remains to be learnt, especially about the policies and programs that could improve the health of the population.
A review of some key findings provides the basis upon which assertions about the social origins of health rely.
Major socio-economic inequalities in mortality are observed in every country that collects relevant data. These inequalities are noted for most major causes of death, across almost all age groups, and persist over time. They are observed in the weight of children at birth (lower socio-economic status groups have lower birth weights) and in the mental and emotional health of children as early as five years of age (Najman et al. 2000). As early in life as it is possible to gather reliable and valid data, children from lower socio-economic status groups have lower IQ scores and higher rates of developmental problems (Najman et al. 2000). There is compelling evidence that, for many, these health and developmental inequalities start before birth and lead via a number of pathways to poorer adult health (Najman et al. 2002). The magnitude (and occasionally direction) of these socio-economically determined health inequalities may change as social conditions change. For example, the mortality gap between upper and lower socio-economic groups seems to be increasing in countries that manifest increasing economic inequalities (Marmot 1999).
There are major health inequalities associated with religious affiliation. Whether religious affiliation is measured by membership of a particular group (eg, Mormons, Seventh Day Adventists) or by the degree to which a person participates in religious activities (frequent attenders versus occasional attenders), the evidence indicates that the more religious have a substantial health advantage (McEvoy and Land 1981; Lyon et al. 1994; Grundmann 1992).