Risk perception and communication.

Public health depends on laypeople’s ability to understand the health-related choices that they and their societies face. The study of risk perception examines that ability. The study of risk communication examines the processes that determine how communication with lay people enhances or degrades their decisionmaking ability. Although focused on decisions involving risk, that research necessarily considers potential benefi ts as well, including the benefi ts of reducing risks (e.g. through medical treatment, lifestyle changes, or improved air quality). Communication is seen as a two-way process. Without listening to people, it is impossible to understand what they know and value, hence impossible to provide them with relevant information in a comprehensible form. The basic science of behavioural decision research describes the general processes that fi nd specifi c expression in risk-related decisions. It provides the conceptual framework, methodology, and theory for this chapter. Risk perception and communication research is conceptually straightforward. First, characterize the decisions that people face, in suffi ciently precise terms to identify the information that is most critical to them. Second, describe people’s existing beliefs and values, in suffi ciently precise terms to understand their roles in riskrelated choices. Third, develop and empirically evaluate communications designed to bridge the critical gaps between what people know and what they need to know, in order to have the best chance of making choices that achieve what they value. These steps are interdependent. For example, descriptive research can reveal unexpected goals, obstacles, and capabilities, forcing revision of the decision analysis; communication failures can force additional research regarding decision-making processes. Executing a communication research programme requires four kinds of expertise: (a) subject matter specialists, (b) risk and decision analysts, for characterizing choices and identifying critical information; (c) behavioural scientists, for characterizing existing beliefs and values, then designing and empirically evaluating communications; and (d) communication practitioners, for executing sustainable programmes. Individuals with each kind of expertise should have fi nal authority in their domain. Behavioural decision research provides extensive guidance on two topics central to this endeavour. One is identifying potential threats to risk-related decision making, along with an understanding Risk perception and communication Baruch Fischhoff 8.8 of the underlying behavioural processes that communications must address. The second is the measurement procedures needed to ensure that people have been properly understood, when creating and evaluating communications. Without proper measurement, it is impossible to assess and address people’s information needs. A particular risk is underestimating laypeople’s decisionmaking competence, thereby denying them the opportunity for active participation in health decisions. That risk is aggravated when communications are disseminated without proper evaluation, after which their audience is held responsible for failing to understand content that was neither clear nor relevant. One should no more release untested communications than untested pharmaceuticals. The chapter seeks to reduce those risks, while helping experts to help laypeople to choose wisely.