In caste endogamy, marriage has to take place within the caste. Brahmin has to marry a Brahmin. In subcaste endogamy, it is limited to the subcaste groups. Here a Shivalli Brahmin has to marry within Shivalli subcaste, a Gangadiagar Vokkaliga has to marry within his sub-caste group, and so on. Endogamy prohibits marriage outside the group. Even today intercaste marriages are not encouraged.
Factors, such as the policy of separation, virtual geographic separation of people, the desire to keep wealth within the group, religious, racial and cultural differences between pt. pies, sense of superiority or inferiority, etc., are said to be the causes of endogamy.
Endogamy as a rule of marriage has its own advantages. It contributes to the group unity and solidarity. It keeps women happier within their group. It helps to preserve the property within the group. It also safeguards the purity of the group. Finally, it helps to keep under secret the strength and weakness and also the professional secrets of-the group.
Endogamy has its, disadvantages also, (i) By dividing the society into small endogamous units, it strikes at national unity, (ii) By limiting the choice of life-partners, it often gives scope for evil practices such as polygyny, dowry system, bride price, etc. (iii) It may also make its followers to develop hatred and contempt for other groups, (iv) It is also said that close-in-breeding caused by endogamy may affect the biological potentiality of the offsprings. For these disadvantages, endogamy is condemned. The modern civilised people are more in favour of exogamy than endogamy.