85 Introduction The potential of raw material movement studies in the reconstruction of past human behaviour is evident in the significant advances that the results of such studies have brought to archaeological research. Much of the information we now acquire about territorial sizes, group interactions and exchange would not have been available if projects dealing with various raw materials/objects provenancing (Merrick et al. 1994; Merrick and Brown 1984; Williams-Thorpe et al. 1984; Williams and Nandris 1977; Nandris 1975) and movement (Féblot-Augustins 1993, 2009; Markó and Péntek 2003-2004; Fisher and Eriksen 2002; Montet-White and Holen 1991; Biró 1984) had not been undertaken. The main shortcoming, however, common in all currently available raw material studies is their focus on local small-scale events which the researchers treat as of purely economic character. It is my conviction that a change in perspective will prove more successful in getting a better insight into the Palaeolithic period. In this paper I will argue that our concern must be towards the behavioural and social aspects of the seemingly purely economic phenomenon of raw material movement. The emphasis must not be the distances over which the materials and items were transported but what these distances imply for the hominin behavioural abilities and the social processes which the Palaeolithic individual creates and participates in. In addition, this paper puts forward the idea that social behaviour is archaeologically visible in the movement of raw materials as long as they are rare, distinctive and their origins can be securely identified (i.e. chemically fingerprinted). Obsidian is one of the best examples in this respect as it is a rock that forms only under very special tectonic conditions and its rarity and distinctive physical properties make it an excellent tool for the investigation of the changing scales of Palaeolithic social life. The approach followed in order to deal with the above research caveat brings together information from East Africa (Kenya, Ethiopia, Tanzania), Central and South- eastern Europe (Hungary, Slovakia, Ukraine, Poland, Czech Republic, Austria, Greece, Bulgaria) and the Near East (Turkey, Armenia, Georgia, Azerbaijan) and encompasses all the phases of the Palaeolithic. By adopting such a holistic method, this research becomes the first project to investigate the use of a particular raw material from a wide chronological and spatial perspective. A total of 127 obsidian-bearing Palaeolithic sites were identified and using the Euclidean theorem of lines the distance from their nearest obsidian source was calculated. These minimum distances were then used to determine the changes of obsidian movement with regards to region and time. At the next level of analysis the obsidian movement ranges were used as a proxy for the scale of Palaeolithic social interactions. Finally, given the nature of my dataset I was interested in examining to what extent ecological variation is responsible for the emerged patterns. Here I will discuss the results of this analysis focusing on the first two examined regions. For a presentation of the Near East data and details on the research methodology see Moutsiou 2011. Title: Changing Scales of Obsidian Movement and Social Networking Theodora Moutsiou Department of Geography, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK Theodora.moutsiou.2005@live.rhul.ac.uk Abstract In this paper I argue that modern social behaviour can be observed in the ability to create and maintain extended social networks where relatedness is successfully sustained in absentia. Archaeologically, modern social behaviour can be detected through the investigation of raw material movement. By concentrating on rare materials 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 complex the behavioural abilities of the individuals involved in the transfers. Information from obsidian-bearing sites spanning the temporal framework of the Palaeolithic and located in two different ecological niches, namely Africa and Europe, will be presented. Using latitude as an exploratory model, the movement of obsidian is investigated. A correlation between obsidian use and long distances is observed. More importantly, the analysis provides strong evidence that obsidian is chosen and transferred significant distances irrespectively of latitude. Subsequently, I argue that the scale of obsidian movement, although conditioned by a number of ecological constraints, is actually rooted in social grounds. It is due to advanced behavioural abilities that obsidian moves and hominins interact and feel related even in absentia. Keywords: obsidian, Africa, Europe, latitude, effective temperature, raw material movement, modern social behaviour