Why are there rules for exogamy and endogamy?

Exogamy and endogamy are social rules that govern marriage practices within and between groups. Exogamy, or marrying outside one's social group, often promotes genetic diversity and strengthens alliances between different communities. Endogamy, on the other hand, reinforces social cohesion and preserves cultural identity by encouraging marriage within a specific group. These rules help maintain social structures and relationships, influencing cultural norms and practices across societies.