Final answer:
The statement that Wilber cites authors believing incest is the universal fundamental taboo is true. Incest taboos exist across all known societies, and the belief in its universality is backed by both historical and contemporary research by sociologists, anthropologists, and psychologists.
Step-by-step explanation:
Wilber cites authors that believe that incest is the fundamental taboo for all cultures. This statement is considered true. Sociologists have determined that an incest taboo, which prohibits sexual relations between parents and their offspring and sometimes extends to other closely related individuals, is a universal norm. The specifics of whom it includes beyond the immediate family vary from culture to culture, but the taboo itself exists in every known society.
Historically, French anthropologist Claude Lévi-Strauss and psychologist Sigmund Freud have both commented on the incest taboo. Lévi-Strauss viewed it as a primary force in creating social structures by separating biological relatives from potential sexual and marital partners. Freud suggested that religious and cultural taboos, such as the incest prohibition represented in stories like the Oedipal complex, serve to maintain societal order by suppressing anti-social instincts.
Overall, despite variations across cultures in defining what constitutes incest, the underlying taboo against it is a well-documented and researched cultural phenomenon.