Why sociologists borrowed a geologist's word for layers of rock
The term stratification comes from the Latin stratum, a flat layer, as in rock. Sociologists use it for the way societies sort people into ranked tiers by wealth, occupation, education and power. Pitirim Sorokin put the concept on the map in 1927, alongside the idea of moving between those layers.
In modern Western societies the usual picture has three broad classes, upper, middle and working, each split again into upper, middle and lower bands. Other societies draw lines by kinship, clan, tribe or caste. Ranking shows up most sharply in complex states and in feudal systems built on the relationship between nobles and peasants. Whether inequality of this kind began among hunter-gatherers or only arrived with farming and large-scale exchange is still debated, but more complex societies generally display more layers.
Scholars note four features. Stratification belongs to a society, not to individuals. It tends to pass from one generation to the next. It is found everywhere yet varies across time and place. And it involves beliefs about status as well as measurable gaps. Social mobility, moving up or down within a lifetime or across generations, is used to judge how open a system is.
Theorists disagree sharply about why it exists. For Marx, class was set by one's relation to the means of production, owners on one side and those selling their labour on the other. Kingsley Davis and Wilbert Moore argued the opposite case, that inequality helps society function: some jobs pay well because they are important and the qualified people to fill them are scarce. Max Weber, influenced by Marx but doubtful of revolution, studied Germany and saw that wealth was not everything. Some aristocrats had political power without money, while some rich families lacked prestige, so he separated class, status and power as independent dimensions.
Ralf Dahrendorf observed that technological economies need educated workers, which tends to swell the middle class. Conflict theorists stress how hard it can be for working people to rise while the wealthy hold political influence.
Source: Social stratification
