The effective options for marriage may be based on common religion, race, colour, ethnic background or age group. (It has also been questioned whether the number of people should be limited to two and whether they should be of opposite sex). Segregated marriages perpetuate ethnic, religious, racial, colour, age and sexual divisions and conflict. Segregated marriages arise out of existing patterns of discrimination.
Segregation in marriage is universal and sometimes enforced by national law. Religious reasons for segregation are diminishing in industrialized countries, although they still exist.