Structural functionalism is a variety of functionalism that came to the fore in social anthropology and sociology in the 1930s, 1940s, and 1950s. Its most direct roots lie in Durkheim's work. Its main focus is on forms of social structure and on the functions of institutions and customs for the persistence of social systems. Radcliffe-Brown was the key figure in this development, and he attracted a following of scholars who were dissatisfied with Malinowski's more general functionalist formulations. They found that the approach provided fruitful possibilities for comparative research, especially in the fields of kinship and marriage and of politics and law, and for the examination of the ways in which even social conflicts may help systems to persist. The approach was criticized by Marxists and others, but many of their arguments appear in retrospect to be unnecessarily polarizing.