A requirement to marry outside one’s group is known as?

The requirement to marry outside one’s group is known as exogamy. This practice encourages individuals to seek partners from different social, cultural, or ethnic groups, thereby fostering broader social connections and alliances outside one's immediate community. Exogamy can serve various functions in society, such as promoting genetic diversity, enhancing social relations, and sometimes even serving as a mechanism for economic or political alliances between different groups.

Endogamy, in contrast, is the practice of marrying within a specific group, often to maintain cultural, religious, or social homogeneity. Assisted marriage refers to marriages that are arranged by someone other than the individuals involved, often with family involvement or through matchmakers, which is not related to the concept of marrying outside one's group. Polygyny is a form of marriage where a man has multiple wives, which does not pertain to the idea of cross-group marriage. Therefore, exogamy is the correct term for the requirement to marry outside one's group.