By Paul Ormerod and Andrew P. Roach
History and Policy website (2010)
Introduction: The authors of this paper have recently been involved in an unusual collaboration, funded by an AHRC Knowledge Transfer Fellowship, to cast light on contemporary issues using historical examples and recent developments in the theory of social networks.
Particularly important has been the modelling of so-called ‘scale free’ networks. These are usually complex, consisting of a small number of very well connected hubs and a large number of far less well connected nodes. Examples include the world wide web and the pattern of human sexual contacts. Although a small number of classic articles in the social sciences can be identified going back almost 100 years which describe scale free networks, it is only in the past decade or so that they have come to be recognised as being applicable to many social and cultural situations. Detailed analysis of their properties only commenced in the late 1990s.
Our most recent work with this model has concentrated on the suppression of a network in the case of the Inquisition and the Cathar heresy in France in the 13th century; and on the spreading of a network in the case of the conversion to Protestantism of England in the mid-16th century. In each case there may be interesting lessons to be learned for the understanding of terrorism and radicalisation throughout the world in the 21st century.