Both A.R. Radcliffe-Brown and Claude Lévi-Strauss were foundational figures in structural anthropology, yet they approached the study of kinship and social structure from distinct theoretical perspectives. While both saw kinship as central to understanding social organization, their methodologies and interpretations differed significantly.

Radcliffe-Brown (Structural Functionalism): Radcliffe-Brown, a proponent of structural functionalism, viewed social structure as an observable reality composed of enduring social relations between individuals and groups. For him, kinship was a system of social relations, rights, and duties that functioned to maintain social order and equilibrium within a society. He focused on empirical observation and synchronic analysis, examining how kinship institutions (like descent groups, marriage rules, and avoidance relationships) contributed to the stability and integration of the social system. Radcliffe-Brown emphasized the importance of descent (patrilineal, matrilineal) in organizing groups and allocating status and property. He saw marriage as a mechanism for creating alliances between groups, but his primary focus was on the functional aspects of these relationships in maintaining the social fabric. His work was largely based on ethnographic studies, aiming to identify universal laws of social structure through comparative analysis.

Lévi-Strauss (Structuralism): Lévi-Strauss, the architect of French structuralism, took a more abstract and cognitive approach. He was less interested in observable social relations and more in the underlying, unconscious mental structures that generate cultural phenomena, including kinship systems. For Lévi-Strauss, kinship was fundamentally a system of communication and exchange, particularly the exchange of women between groups, which he termed 'alliance theory.' He argued that the incest taboo, a universal prohibition, compels exogamy (marriage outside one's group), thereby forcing groups into alliances and creating a complex web of social solidarity. This exchange, he believed, reflected universal principles of reciprocity and the human mind's tendency to organize the world through binary oppositions. He distinguished between 'elementary structures' of kinship (where marriage rules explicitly define who one can and cannot marry) and 'complex structures' (where rules are negative, only stating who one cannot marry). Lévi-Strauss's method involved analyzing myths, rituals, and kinship terminologies to uncover these deep, universal structures of thought, often employing a more diachronic and comparative approach than Radcliffe-Brown.

Comparison: In essence, Radcliffe-Brown studied kinship as a concrete social institution with observable functions for social cohesion, focusing on descent and the maintenance of existing structures. Lévi-Strauss, conversely, saw kinship as a manifestation of underlying mental structures, focusing on alliance, exchange, and the universal cognitive principles that generate these systems. While both contributed immensely to our understanding of kinship as a structural phenomenon, their theoretical lenses and methodological priorities were distinct, offering complementary insights into the complexities of human social organization.