Also found in: Wikipedia.
incest taboothe prohibition on sexual relations between certain categories of kin, generally those of close blood relationship. Some form of incest taboo is found in all known societies, although the relationships which the taboo covers vary. Most common are child-parent and sibling relationships. Some societies actively encourage sexual relationships between cousins, whereas in other societies such relationships would be seen as incestuous. Other societies may not prohibit sexual relationships between certain categories, but would prohibit marriage between the same people.
Various explanations have been put forward for the universality of some form of incest taboo. Some have argued that the now known genetic consequences explain this. But not all human groups would have made this link, and cousin marriage preference would probably have not existed if this was the case. LÉVI-STRAUSS argued that it existed to ensure that people marry out of their social group and thus form alliances with other social groups. (However, sexual prohibitions are not the same as marriage rules.) FREUD's explanation rests on the strong attraction of incestuous relations, particularly between son and mother, and the taboo exists to reduce conflict within the nuclear family. The internalization of the taboo is, for Freud, an important part of the psychological development of the individual (see OEDIPUS COMPLEX).
Given the variety of ways in which the taboo is expressed, emphasis on its universality and hence on universal explanations, is probably misplaced. Greater emphasis on why particular societies designate particular relationships as incestuous and not others may be a more fruitful line of inquiry.