Introduction

Health depends, in part, on deliberate decisions. Some are private, such as deciding whether to wear bicycle helmets and seat belts, follow safety warnings, use condoms and fry (or broil) food. Other decisions involve societal issues, such as whether to protest about the siting of an incinerator or halfway house, vote for fluoridation and ‘green’ candidates or support sex education.

Sometimes, single choices have large effects on health risks (e.g. buying a car with airbags, taking a dangerous job, getting pregnant). At other times, the effects of individual choices are small, but accumulate over multiple decisions (e.g. repeatedly ordering broccoli, wearing a seat belt or using the escort service in parking garages). Yet other times, choices intended to reduce health risks achieve nothing or the opposite (e.g. responding to baseless cancer scares, subscribing to quack treatments).

In order to make health decisions wisely, individuals must understand the risks and benefits associated with alternative courses of action. They also need to understand the limits to their own knowledge and to the advice proffered by various experts. This chapter considers how to describe people's beliefs about health risk issues, as a step toward designing (and evaluating) interventions designed to improve their choice. A fuller account would also consider the roles of emotion, personality, culture and social processes (Lerner & Keltner, 2000).