Sexual relations between persons who, because of the nature of their kinship ties, are prohibited by law or custom from intermarrying.
The incest taboo is generally universal, although it is imposed differently in different societies. Usually, the closer the genetic relationship between two people, the stronger and more highly charged is the taboo prohibiting or discouraging sexual relations. Some sociobiologists consider that inbred populations have diminished reproductive success and become gene pools for hereditary disorders. Some cultural anthropologists argue instead that the incest prohibition, with the corresponding rules of child abuse ).