Recent risk perception research focuses on the role of emotions. This chapter examines the framework that underlies most empirical risk perception research, which sees emotions as the opposite of, and categorically distinct from, rationality. It discusses the Dual Process Theory (DPT) framework in detail and argues that it cannot do full justice to the phenomena involved in laypeople's risk perceptions and emotions. DPT was developed by Daniel Kahneman and others. Paul Slovic reviews various studies that point to the important role that affective mechanisms play in decision-making processes. According to Slovic and his colleagues, emotions are an important guide in determining people's preferences, but emotions can also be prejudiced and closed to new information: the affect heuristic enables people's to be rational actors in many important situations. Seymour Epstein has developed an account called cognitive-experiential self-theory (CEST) according to which there are two 'interactive modes of information processing, rational and experiential'.