Since prehistory, all societies have perceived hierarchy among their members. Leaders and followers, strong and weak, rich and poor: social classifications are universal. Humans have invented numerous ways to classify people—by wealth, power, or prestige; by ability, education, or occupation; even by where they live. The term "social class" originally referred to groups of people holding similar roles in the economic processes of production and exchange, such as landowner or tenant, employer or employee. Such positions correspond to different levels of status, prestige, and access to political power, but social class eventually took on a more generic meaning and came to refer to all aspects of a person's rank in the social hierarchy.
Belonging to a social class is not merely an objective fact, but is generally accompanied by a
Social class may be ascribed at birth, as with royalty or nobility, or with castes in Hindu societies. More commonly, however, a person's position at birth is modified by his or her achievements, typically through education, occupation, or income. Class cannot be measured directly. Instead, indicators of socioeconomic status, typically based on educational attainment, income, wealth, or occupation, are used. While few would consider these to be ideal indicators of social class, they nonetheless show consistent associations with health status, such that poorer or less educated people die younger and experience more illness and disability than richer or more educated people. These indicators each have strengths and shortcomings.
A simple occupational classification has been used in Britain throughout the twentieth century for analyses linking social class and health. The British Registrar General for Births and Deaths ranks occupations in six broad categories that reflect a judgment of the skill level and social prestige of each occupation. This has been followed by other, more complex classifications, such as the 100-point occupational scale of Tremain. This applies internationally and allows comparisons between developing and industrial countries. These categories have the advantage of capturing the notion of shared culture implicit in social class,
but they are limited because there is no adequate way to classify people who are not in the labor force, such as retired people, housewives, or students. Furthermore, the status of occupations changes with economic development, complicating comparisons across times and across cultures. Finally, occupation shares a limitation with income, in that reverse causality may occur whereby occupational status (or income) may be influenced by the level of health.
The advantages of education as an indicator of social status include simplicity and universality: educational level can be recorded for all adults, whether working or not, and it is less likely than occupation or income to be influenced by health. But education is generally finished in early adulthood, and may no longer reflect a person's status in later years. Care must also be taken when drawing comparisons of educational levels across generations, since educational attainment changes from generation to generation.
Income or wealth are also frequently used as indicators of social class, and hold the advantage of sensitivity to variations in a person's status over time. Wealth is not simple to record, however; data on income must be supplemented by information on the number of people supported by the income, and on other assets such as savings and property. Because of shortcomings in each of
these indicators, several authors have used indicators that combine education, occupation, and income.
While socioeconomic status is generally considered a characteristic of individuals, contextual measures of social class may also be relevant in explaining patterns of health. Thus, for a population we may record not only the average level of income or wealth, but also the extent of income disparities, or class divergence, in the society. Such indicators can indicate social class characteristics of the society, rather than summarizing patterns in the society.
Contemporary epidemiologic analyses assume that it is not so much social class per se that influences health, but characteristics associated with class. There are several channels through which class or socioeconomic position may influence health:
- Certain health hazards may be directly associated with social position, such as exposure to hazardous substances or processes in the workplace.
- Alternatively, social class may influence health via behaviors that follow social patterns, such as diet, cigarette smoking, or leisure-time physical activity.
- Wealth can influence health directly, by providing access to safe and healthy housing, adequate food, and medical care and supplies when needed. Wealth also enhances educational attainment in a person's children, and so influences their subsequent earning capacity; in this manner the association between poverty and health tends to perpetuate itself across generations.
- Education also facilitates access to information that can benefit health. More educated people are better able to communicate with their physicians and interact with the health care system, and make informed choices among treatment options.
- Higher social status is associated with attitudes, such as positive self-esteem or a sense of being in control of one's life, that are positively associated with a range of indicators of health (especially mental health). Such feelings are difficult to maintain when a person is unemployed.
Contemporary analyses of social class in health research have evolved from using it as a simple classification toward using class as a starting point for a more complete analysis of possible channels of influence. The next stage, perhaps, will be to incorporate an understanding of social class dynamics into designing approaches to prevention and health promotion.
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Krieger, N.; Williams, D. R.; and Moss, N. E. (1997). "Measuring Social Class in U.S. Public Health; Research: Concepts, Methodologies, and Guidelines." Annual Review of Public Health 18:341–378.
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Szretzer, R. S. (1984). "The Genesis of the Registrar General's Social Classification of Occupations." British Journal of Sociology 35:522–546.
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Wilkinson, R. G. (1996). Unhealthy Societies: The Afflictions of Inequality. London: Routledge.