family: a social group, originating in marriage & children born in wedlock, united by legal/economic/religious bonds, sexual rights/prohibitions, is a universal phenomenon
2 main principles:
1. gendered division of labor, creating mutual dependencies between couple
2. incest prohibition, creating continuous dependencies between 2 clans
1. marriage is presenting a woman to another man as a gift, real purpose is not to gain a wife but to gain brothers-in-law