Anthropologists have long spoken about initiation rites in pre-modern societies. For example, adolescent boys in the Fulani tribe in West Africa engage in whipping battles with other adolescent boys as a rite of passage into adulthood. Related ordeals for adolescent males are found across different tribes in New Guinea. Many rites in modern Western culture may not be recognized as initiation rites per se although they may well serve that function. For example, boot camp in the marines, hazing in fraternities, and thirty-six-hour work shifts for medical residents may function as initiation rites. Initiates must go through painful and often humiliating trials before being accepted into an exclusive group.