Laws and policies controlling Aboriginal people’s lives through much of the twentieth century were deeply influenced by racial theories of the time. In the early part of the century, social Darwinist assumptions about the survival of the fittest led to a belief that Aboriginal people would die out. In the same period there were eugenicist views based on biological determinism which advocated that Aboriginal ‘blood’ should be bred out through ‘miscegenation’. Anthropological ideas about culture associated ‘traditional’ Aboriginal culture with people of full Aboriginal descent while people of mixed descent were assumed to be in some cultural limbo, destined for assimilation into mainstream Australian society. A caste system was constructed under Australian laws for people of Aboriginal descent. There were ‘full-bloods’, ‘three-quarter-castes’, ‘half-castes’, ‘quarter-castes’ (also referred to as ‘quadroons’) and ‘octoroons’

Brock, P. & Gara, T. (2017). From segregation to self-determination in the twentieth century. In Colonialism and Its Aftermath: A history of Aboriginal South Australia Adelaide (pp. 37-56). Wakefield Press. Available here