Pre-Nuragic Sardinia (Late Neolithic and Chalcolithic, c. 4400-2300 BC) was a period of changing social and cultural practices, where both insular developments and external influences contributed to distinctive traditions across the island. This is epitomised by the domus de janas: rock-cut tombs that were, uniquely for this period in the Mediterranean, increasingly embellished with architectural, representational, and abstract art. In line with traditional approaches, these monuments have been the subject of many typo-chronological and cultural-historical studies, and yet few have explored the social role of the tombs in their wider prehistoric contexts. This thesis explores the hypothesis that the domus de janas were central in the creation and articulation of group social identities in the pre-Nuragic period. Whilst drawing heavily on earlier works, it proposes that the artistic embellishment of tombs can be used to reconstruct a ‘social geography’ of Sardinia; in other words, by identifying spatial clusters and connections visible through the distribution of decorative motifs across the island. To do so, this study has created databases of the 492 decorated domus de janas and of all rock-cut tomb cemeteries in Sardinia, and uses statistical and computational methods in R Studio and QGIS, combined with comparative approaches. In particular, it suggests that examining statistical similarity is a method through which to consider difference, which, when placed in its geographical, political, and socio-cultural context, is used to investigate not only the nature of distinctions present between communities, but also the reasons why they may have developed in this way. Analysing and evaluating data at different scales, the study generates an island-wide view of cultural difference – and similarity – in this period, as well as regional variations in the social roles of tombs. Overall, it argues that distinct identity constructions and expressions are visible across the island, and that these were the result of several factors including cultural traditions, trade and exchange, and topography. Placing the tombs and their social function in the wider context of Mediterranean rock-cut tombs, it also contributes to debates surrounding connectivity and insularity in the Late Neolithic and Chalcolithic periods.