Rigid social stratification, in which ultimate lineage or parental position or profession determines occupation, marriage partner, rank or title, communal responsibilities, and the like, can be characterized as the caste system. The caste system, unlike the class system, or the mediaeval European system of the three estates of nobility, clergy, and commons, does not allow for upward mobility, at least in a single lifetime. As practised on the Indian sub-continent, it has been buttressed by sacred writings which, like the Old Testament, emphasize the concepts of purity and pollution. The effect of the caste system is repression and enslavement of generations of individuals and an incalculable retardation of national development owing to the fragmentation of society.
The caste system is best known in India where concepts like 'untouchables' still exist. It obtains around the world amongst immigrants, and descendants of immigrants, from India. The social status of the different caste groups there varies from state to state and sometimes between different areas in the same state. It has been estimated that there are may be as many as 1,000 castes and sub-castes. The upper castes range from the Brahmin priestly caste to the landed intermediate castes and represent some 20% of the population. The backward castes include the cultivators, small landowners and cattle herders and represent sme 34% of the population. The scheduled castes, considered as outcastes, include those with tainted occupations such as cleaning toilets, burning the dead and cobblers and represent some 16% of the population. Outside the Hindu caste system are the so-called tribal or indigenous communities representing 12% of the population. The outcastes are the menial, depressed tribes or castes or they have been expelled from their own tribe or caste permanently or temporarily. However, wherever a priestly class has been able to dominate a society, like the Levites among the Jews, ritual and secular rules of purity have emerged; and where minority ethnic groups have also been present, they have conveniently been termed unclean or 'beyond the Pale'. This is true also of minority non-believers, so that caste system ideas enter into religious conflicts, for example in Assam and Punjab. In the state of West Bengal there are 41 scheduled tribes and 63 scheduled castes, accounting for only 26% of the population. The balance, 74%, are 'outcastes'. In 1994 it was reported that throughout India rapes and murders of lower-caste women by upper-caste men had increased.