The Fourth World is an extension of the three-world model, used variably to refer to The term is not commonly used.
Spanish sociologist Manuel Castells of the University of Southern California Annenberg School for Communication has made extensive use of the term fourth world.
[2][3] The term was coined in 1969 by Father Joseph Wresinski when he renamed the charity he had founded in 1957 with families from the Noisy-le-Grand (France) shanty town to ATD Quart Monde.
[6] Since 1979, think tanks such as the Center for World Indigenous Studies have used the term in defining the relationships between ancient, tribal, and non-industrial nations and modern industrialised nation-states.
[8] In the Indian left movement, M. P. Parameswaran's ideas on the fourth world caused widespread debates, which eventually led to his expulsion from the Communist Party of India (Marxist) in 2004.