“All animals, including humans, mate: some for life and some not; some with a single individual of the opposite sex and some with several. Only marriage, however, is sanctioned by legal, economic, and social forces. Anthropologists have tried to identify the common elements in different types of marriage to find the features that are essential or otherwise. They have also focused on the different forms of marriage and the elements involved, sexual, legal, economic and political and the futility of searching for a universal definition. In many tribal societies, marriage involves contracts or alliances between different descent groups, and is not a relationship between individuals. It is a transfer or flow of rights.”