Final answer:
The incest taboo is the principle that prohibits sexual relationships between culturally specified relatives, such as between parents and their offspring and potentially other close relatives.
Step-by-step explanation:
The principle that prohibits sexual relationships between certain culturally specified relatives is known as the incest taboo. This is a universal cultural norm that disallows sexual relations between parents and their offspring and often extends to other close kin. In societies across the globe, though the specifics of the prohibition can vary, the incest taboo serves as a form of exogamy, which is a rule that mandates individuals to seek marriage partners from groups other than their own close relatives.
Polygamy, on the other hand, refers to a marriage that includes more than two partners and takes forms such as polygyny (one man with multiple wives) or polyandry (one woman with multiple husbands). Endogamy is the practice of marrying within a specific social group, caste, or ethnic group, obeying the social rule of marrying only within the limits of the group. Monogamy is a marriage structure where an individual has only one partner during their lifetime or at any one time (serial monogamy).