Trust in motives, trust in competence: Separate factors determining the effectiveness of risk communication

According to Siegrist, Earle and Gutscher's (2003) model of risk communication, the effect of advice about risk on an agent's behavior depends on the agent's trust in the competence of the advisor and on their trust in the motives of the advisor. Trust in competence depends on how good the advice received from the source has been in the past. Trust in motives depends on how similar the agent assesses the advisor's values to be to their own. We show that past quality of advice and degree of similarity between advisors' and judges' values have separate (non-interacting) effects on two types of agent behavior: the degree of trust expressed in a source (stated trust) and the weight given to the source's advice (revealed trust). These findings support Siegrist et al.'s model. We also found that revealed trust was affected more than stated trust by differences in advisor quality. It is not clear how this finding should be accommodated within Siegrist et al.'s (2003) model.