The Impact of Social Class on Health

The impact of social class on health is obvious: Around the world, in every age group and racial or ethnic group, those with higher social class status have lower rates of morbidity and mortality. The relationship between social class and health holds true for all major and most minor causes of death and illness, regardless of how researchers measure social class. For example, in the United States heart disease occurs three times as often and arthritis twice as often among low-income persons compared to more affluent persons. Moreover, these health differences appear across the en- tire income scale, with each group on the social class ladder having better health than the group just below it. And when researchers control for all known individual risk factors (such as obesity and smoking), the impact of social class on health declines only slightly.

That impact begins at birth, with infant mortality significantly higher among the poor. The evidence linking social class to health, then, is extremely strong. However, some sociologists (most notably Richard Wilkinson) have argued that income inequality—the gap in income between a nation’s poorest and wealthiest—rather than income itself, may best explain why some nations are healthier overall than others. These theorists point, for example, to data showing that as income inequality declined in the United States from around 1960 to 1980, life expec- tancy rose among all social classes. Other researchers, however, point to data suggesting that income alone affects health more than does income inequality. For example, since 1980, income inequality has soared in the United States, but life expectancy fell only for poorer Americans. This suggests that income affects health more than does in- come inequality. More research is clearly needed to tease out how and whether income inequality affects health.