In his 1958 book Moral Basis of a Backward Society, Edward Banfield introduced the term amoral familism to describe social relations and values in a poor rural community in southern Italy. In my analysis, I propose to abandon the value-laden epithet "amoral" and consider familism as an evolutionary adaptive strategy activated in times of scarcity or crises. I base the thesis of the evolutionary roots of familism on the inclusive fitness theory (Hamilton 1964) and the theory of kin and reciprocal altruism (Trivers 1971). The perspective of evolutionary psychology makes it possible to see the positive functions of familism and to propose a new biological-cultural understanding of familism. Familism has so far been diagnosed primarily "indirectly" in sociological studies of bonding (and bridging) capital and in research on social trust conducted as part of cyclical social surveys such as the World Values Survey and the European Social Survey. In the search for accurate measures of biological-cultural familism we can additionally turn to the research of cross-cultural psychologists conducted for international management. I argue that the dimension of particularism on the 7-dimensional cultural map of Fons Trompenaars and Charles Hampden-Turner (2002) and the dimension of in-group collectivism on the 9-dimensional cultural map of the GLOBE project (House et al. 2004), can valuably complement the measures used in sociological sciences and make the diagnosis of familism more reliable. Finally, I call for in-depth research on Polish familism aimed at testing whether it is possible to build bridging capital on the basis of familist bonding capital.