Theodora Moutsiou (Royal Holloway, University of London)

The concept of modern hominin behaviour has received a lot of attention in recent archaeological research but the problem of developing a precise definition remains unsolved. Despite the different approaches, there is a general consensus that sees planning depth, intentionality, choice and a sense of aesthetics as essential components of a mind that functions in a modern way. The social aspect of modern cognition is reflected on the ability of hominins to engage in intensive interactions and to build and maintain extended social networks. Archaeologically, modern social behaviour can be detected through the investigation of raw material movement. By concentrating on materials that are rare, distinctive and their origins can be securely identified it is possible to reconstruct the dimensions of the exchange networks involved in their circulation. Using this information, the scale of social interactions can be inferred. The greater the distances of raw material movement the more advanced the cognitive and behavioural abilities of the individuals involved in the transfers.

Obsidian-bearing sites spanning the temporal framework of the Palaeolithic and located in Africa and Europe are analysed with the aim of elucidating the evolution of modern social behaviour. Obsidian is a rock that forms only under very special conditions; its geological sources are infrequent and distinguished from each other on the basis of unique chemical properties. As such it is possible to reconstruct the distances of its movement and use these data to infer the scale of social life during the Palaeolithic. A strong correlation between obsidian use and long distances is observed implying that the hominins involved in the circulation of the specific material were behaving in a socially modern way. According to the obsidian data the evolution of modern social behaviour has been a gradual process that was initiated in East Africa at least during the Middle Stone Age.