82:5.7

Many tribes finally forbade marriages within the clan; others limited mating to certain castes. The taboo against marriage with a woman of one’s own totem gave impetus to the custom of stealing women from neighboring tribes. Later on, marriages were regulated more in accordance with territorial residence than with kinship. There were many steps in the evolution of in-marriage into the modern practice of outmarriage. Even after the taboo rested upon in-marriages for the common people, chiefs and kings were permitted to marry those of close kin in order to keep the royal blood concentrated and pure. The mores have usually permitted sovereign rulers certain licenses in sex matters.