“…Moreover, several of these studies claim to have identified evidence of nuclear families. A rich historiography generally supports that the Roman family was nuclear [8][9][10] based on various sources, especially funeral epigraphy [11][12][13] and the analysis of Roman law [14], which inheritance rules were inconsistent with a high kinship intensity system. After the fall of the Roman Empire-though before the advent of the MFP-population censuses [15][16][17][18], analyses of house sizes [19], as well as family organizations depicted in Saints vitae [20] all suggest that the nuclear family was also dominant then, while Saint Augustine [The City of God, XV, 16] testifies that cousin marriage was already socially rejected in the fifth century (we provide further discussion of this historical evidence in the Supporting Information).…”