Intelligence, education, and mortality

Socioeconomic status can be indexed in a variety of ways, but usually on the basis of an individual’s occupational social class, income, education, and housing tenure. Data accumulated over several decades show that these characteristics are associated with differences in health, particularly within affluent societies. With the exception of few outcomes—incidence of breast cancer in women and selected injuries—poorer health is more common in poorer people.1 Moreover, this gradient seems to be apply across the full socioeconomic range, rather than being confined to the most disadvantaged end of the spectrum. A worldwide reduction in these differentials has become a priority for many governments, including that of the United Kingdom,1 and for the World Health Organization, which in 2005 launched the Global Commission on Social Determinants of Health.2

In endeavouring to ameliorate health inequalities, it is important to understand the underlying causes; two BMJ studies attempt to describe the gradient more clearly3 and understand what factors explain it.4 In the linked study from Norway (doi: 10.1136/bmj.c654), Strand and colleagues assess the relation between educational inequalities and mortality from 1960 to 2000.3 In a recently published study, Lager and colleagues investigated the association between early IQ, educational attainment, and mortality in Sweden. …