The Iberian Copper Age is a period dominated by the emergence of early complex societies. In sharp contrast with the preceding Neolithic, the Chalcolithic is characterized by agricultural intensification, population aggregation, political centralization and the appearance of ‘mega-villages’ on the landscape. Previous research has focused on the phenomenon of collective burial to suggest that these broad-scale social processes are underwritten by a ‘communally-organized society’. However the internal organization of such communities is still poorly understood, particularly because the taphonomy and social function of such collective burials are underexplored. At 113 ha in size, Marroquíes Bajos is one of the largest settlements known for the time period, and contains evidence of four different burial programs. This project’s bioarchaeological analysis of the mortuary variability at the site will allow for the investigation of whether Iberian Copper Age societies were collectively organized, or whether significant disparities in health, diet or material culture existed among the social units being represented in these burials Through osteological analysis, isotopic analysis of diet, AMS radiocarbon dating, and an archaeological analysis of tomb form and grave goods, my investigation at Marroquíes Bajos will allow for a more nuanced reconstruction of the ways in which Copper Age societies were organized, while deepening our understanding of how and why collective burials were used by prehistoric populations.