risk perceptions arising from new technologies, accidents, threats and media scares. Notes 1 Calibration implies setting the structure of the model and its parameter values in such a way that its results are sufficiently close to empirical observations, with this sufficiency criterion depending on the purpose of the model. Calibration thus normally requires empirical data on the processes that the model is representing. These data can be acquired through surveys, statistical analysis of empirical data, experiments, questionnaires, etc. ( Longley et al. 2009 ; Sargent 2003 ). 2 This generally accepted definition implies that risk perceptions cannot be 'wrong', though they can be inaccurately measured. They may seem to be illogical or irrational but only from someone else's subjective viewpoint. 3 An agent based model could have also been used. However, our analysis deliberately avoids reducing agency to individuals. Indeed, the CT tradition is critical of methodological individualism -- the idea that the 'aggregation' of decisions by individuals can explain broad society-wide developments. We therefore construct our model based on what we called 'cultural archetypes' rather than to focus on the individual and build a micro-simulation upwards, and, following the sociological tradition of mile Durkheim and Mary Douglas, set a group of agents belonging to the same cultural archetype as the unit of analysis. 4 Throughout the paper, the terms agent or individuals -- interpreting events in constructing their perceptions of risk -- refer to an archetypal representative of each cultural bias, not a specific or 'real' individual. 5 In