Everyday behaviors and decisions have a dramatic impact on morbidity and mortality1; it is estimated, for example, that 30% of all cancers are attributable to tobacco use.2 The risks of cervical cancer, cardiovascular disease, and car fatalities are reduced greatly by HPV vaccination,3,4 cholesterol screening,5,6 and seat belt use,7 respectively. Consequently, it is important to devise strategies to encourage greater engagement in risk-reducing behaviors and avoidance of risk-increasing behaviors. To that end, researchers have devised several theoretically driven interventions to change attitudes, construct environments, provide resources, strengthen social support, and influence peer norms in ways conducive to healthy and safe behaviors.8–12
A key approach to encouraging healthy behaviors and decisions is the effective communication of risk—both at the population level and the individual level. People need to understand how their behaviors influence their health and safety risks, and perhaps most importantly, how current and future behaviors might reduce those risks. This is a major assumption of many models of health behavior such as the Health Belief Model13 and the Precaution Adoption Process Model.14 Meta-analyses suggest that risk perceptions are significantly (though modestly) related to health behaviors (e.g., Brewer et al.,15); one meta-analysis showed that experimental manipulations of risk perception can have significant effects with moderate effect sizes on health intentions and behaviors.16 Thus, it is essential to know how to best communicate health risks clearly and effectively. Importantly, one must do so while minimizing the potential for unintended consequences. Consider a study by Stock et al.17 in which sexually active participants learned about a peer who contracted HIV after just one sexual encounter. Rather than extrapolate from that person’s experience to their own by elevating their perceived risk, study participants came to see themselves as even less at risk because, they reasoned, if they hadn’t been infected yet, they were likely immune. It is also important that risk communications do not elevate risk perceptions so far that recipients become overly anxious and paradoxically less interested in risk reduction.
In this chapter, we review lessons learned from the extensive literature on risk communication. We begin by first identifying the contexts within which risk communication takes place and by then discussing the ways in which people think about and understand risk—an important precursor to considering what types of risk communications will be most effective. We then address how people construe numerical information, and consider implications for communicating risk. This is followed by a consideration of many of the psychological factors (e.g., motivational, emotional) that are present in risk communication contexts—factors that can be as or more important than comprehension when assessing the potential impact of risk communications. Finally, we consider how to strengthen the connection between risk communication and subsequent action, the extent to which communicators of risk information can be trained, and enduring needs for further research in this area.