Managing decision-making with certainty of threat

Several factors, such as emotion and uncertainty of the outcome, influence decision-making. We assessed decision-making during a risky event (natural hazard, focusing here on two types of volcanic threats) by manipulating the certainty of lethal threat in an information campaign. We hypothesized that the reduction of uncertainty of lethal threat in an information campaign would improve behavior through more suitable choices by reducing the use of emotional choices. In the scenario that occurred in a familiar place, participants who received information with uncertainty of lethal threat presented more emotional and comfortable choices, such as staying at home, rather than detached ones, such as leaving the area. These were either appropriate (for volcanic ash cloud) or inappropriate (for pyroclastic flow). The certainty hypothesis was partially validated, as certainty influenced the quality of choice in the scenarios that took place at home. Furthermore, participants in the volcanic disaster context presented less suitable decisions compared to those in the neutral context, which was discussed in terms of the presence of emotions, such as fear of volcanic eruption. Our results highlight the importance of controlling the comforting emotional aspect of the home environment in any information communication.