Developing some means of affecting public risk perception and risk acceptance—means that would be compatible with our participatory form of democracy—became important to risk managers when early risk perception research showed that public thinking about risks differed from, and was often unaffected by, assessments of risk by technical experts. The field of risk communication research was developed during the 1980s to devise ways of bridging the public/expert risk judgment gap. In the 1990s, Slovic argued that risk communication had not yet lived up to its promise. The primary reason cited by Slovic for this failure was lack of attention to the key role of trust in risk communication. Given a context of trust, he observed, risk communication seemed easy. But, lacking trust, risk communication seemed impossible. Slovic concluded that trust is more fundamental to conflict resolution than is risk communication. Inspired by Slovic, a small group of risk researchers began to focus on studies of trust in risk management, eventually developing the TCC Model (Trust, Confidence, and Cooperation), the basic form of which is shown above.
At the core of the TCC model is the distinction between trust and confidence. Trust is social and relational; confidence is instrumental and calculative. We define trust as the willingness, in the expectation of beneficial outcomes, to make oneself vulnerable to another based on a judgment of similarity of intentions or values. Confidence is the belief, based on experience or evidence (e.g., past performance), that certain future events will occur as expected. The basis for trust is fundamentally a judgment of similarity between one person and another, that the person to be trusted would act as the trusting person would. Thus, trust is based on social relations, on shared values. The basis for confidence is past performance, or institutions designed to constrain future performance. Both trust and confidence, in a range of combinations, can lead to various forms of cooperation.
We also distinguish two basic types of trust, one within groups, and one across groups. Within-group trust includes what we call social trust (trust at a distance, based on limited information) and interpersonal trust (trust close at hand, based on repeated interaction). Across-group trust is called general trust (trust among strangers). Social trust and general trust are most relevant to risk management contexts. As the TCC Model shows, confidence is dependent on trust: Any judgment of confidence presupposes a relation of trust. That is, the descriptions on which confidence is based are justified and accepted only within the group or community of trust that generated them.