Portugal was long a closed, hierarchical, elitist, rigidly structured society whose social institutions seemed to be more nineteenth century than twentieth. Portugal was called a "society of uniforms" because people could be identified and their class rank determined by the clothes they wore, their manner ออออof speech, and how they walked and carried themselves. Social structure was seen as immutable, and persons were expected to accept their station in life. Other than a few slots in the university or the military officer corps, few opportunities existed for upward mobility.

The Revolution of 1974 destroyed, undermined, or at least precipitated the toppling of many of these hierarchical institutions. In the years since then, Portuguese society has become more flexible. More opportunities for social mobility appeared, and old categories of place and position became blurred. Portuguese society became more egalitarian, pluralist, and democratic, and there was more of what the Portuguese liked to call movimento (change, dynamism, or movement).

In the years following the mid-1970s, the country's middle class grew in size and solidarity, the working class enjoyed a rising standard of living, and the number of entrepreneurs and technicians increased markedly. The most significant of these changes was the growth of a sizeable and more stable middle class that offered the hope for a more stable and democratic country. The middle class largely replaced the old elite and came to dominate most Portuguese social and political institutions: the political parties, the church, business, the military officer corps, government and bureaucracy, and even union leadership. Thus, a major class shift occurred. It had begun earlier in the century, continued through the Salazar era, and by the early 1990s appeared to have been consolidated. This shift from upperto middle-class leadership could give Portugal the basis for stable, democratic rule that it lacked before.

Data as of January 1993