Risk Perception, Heuristics and Epidemic Spread

During an outbreak of an infectious disease, people often change their behaviour to reduce their risk of infection. In a given population, the levels of perceived risk of infection vary greatly among individuals. The difference in perception could be due to a number of different factors including varying levels of information regarding the pathogen, quality of local healthcare, availability of preventive measures, individual and group usage of heuristics in the decision-making process. First we discuss the rigorous assessment of the risk, then we describe how our brain assesses the risk through the use of heuristics that are still rooted in animal evolution. Then we discuss the impact and the role of mass media and social networks in modulating risk perception. Next, we show how mathematical modelling is challenged by multi-scale epidemiological problems where the risk perception level is coupled with all the other microscopic and macroscopic levels. Finally, we draw future scenarios of personal risk evaluation through self-monitoring devices and personal genomics. The aim of this chapter is to discuss the importance of risk perception related to the spreading of a disease and to present a variety of ideas that could be fruitfully explored through modelling.