The article considers the fine dividing line between the use and misuse of ethnographic material "to the benefit of general social development". It questions both ethnology, whose theoretical structures have contributed to ideologies of European ethno-centrism, and cultural anthropology, the beginnings of which are even more questionable since it represented official principles of colonial administrations and helped shape the foundations of policies of assimilation through which "modern" countries would "civilise savages". It is thus directly or indirectly responsible for the ethnocide of many indigenous communities. After the Second World War anthropology widened its scope: from advocacy and intervention to participation in the social life of local communities, interaction and activism. The contribution points to the different pre-war and post-war approaches of applied anthropology in two Latin American cases - indigenism and engaged interactive cooperation in the programme sumak kawsay.eth