Reconstructing Mesolithic social networks on the Iberian Peninsula using ornaments

Archaeologists have been reconstructing interactions amongst hunter-gatherer populations for a long time. These exchanges are materialised in the movements of raw materials and symbolic objects which are found far from their original sources. Social network, i.e. the structure constituted by these interactions, is a well-established concept in archaeology that is used to address the connectivity of hunter-gatherer populations. The heuristic potential of formal network analysis, however, has been scarcely exploited in prehistoric hunter-gatherer archaeology. Here, social network analysis is used to analyse the interactions amongst hunter-gatherers on the Iberian Peninsula in the Early and Late Mesolithic (10,200 to 7600 cal BP). We used ornaments to explore social interaction and constructed one network per phase of the Iberian Mesolithic. We applied a three-steps analysis: First, we characterised the overall structure of the networks. Second, we performed centrality analysis to uncover the most relevant nodes. Finally, we conducted an exploratory analysis of the networks' spatial characteristics. No significant differences were found between the overall network topology of the Early and Late Mesolithic. This suggests that the interaction patterns amongst human groups did not change significantly at a peninsular scale. Moreover, the spatial analysis showed that most interactions between human groups took place over distances under 300 km, but that specific ornament types like Columbella rustica were distributed over more extensive distances. Our findings suggest that Iberian Mesolithic social networks were maintained through a period of environmental, demographic and cultural transformation and that interactions took place at different scales of social integration.