Public Response to a Near-Miss Nuclear Accident Scenario Varying in Causal Attributions and Outcome Uncertainty.

Many studies have investigated public reactions to nuclear accidents. However, few studies focused on more common events when a serious accident could have happened but did not. This study evaluated public response (emotional, cognitive, and behavioral) over three phases of a near-miss nuclear accident. Simulating a loss-of-coolant accident (LOCA) scenario, we manipulated (1) attribution for the initial cause of the incident (software failure vs. cyber terrorist attack vs. earthquake), (2) attribution for halting the incident (fail-safe system design vs. an intervention by an individual expert vs. a chance coincidence), and (3) level of uncertainty (certain vs. uncertain) about risk of a future radiation leak after the LOCA is halted. A total of 773 respondents were sampled using a 3 × 3 × 2 between-subjects design. Results from both MANCOVA and structural equation modeling (SEM) indicate that respondents experienced more negative affect, perceived more risk, and expressed more avoidance behavioral intention when the near-miss event was initiated by an external attributed source (e.g., earthquake) compared to an internally attributed source (e.g., software failure). Similarly, respondents also indicated greater negative affect, perceived risk, and avoidance behavioral intentions when the future impact of the near-miss incident on people and the environment remained uncertain. Results from SEM analyses also suggested that negative affect predicted risk perception, and both predicted avoidance behavior. Affect, risk perception, and avoidance behavior demonstrated high stability (i.e., reliability) from one phase to the next.

Cumulative Response to Sequences of Terror Attacks Varying in Frequency and Trajectory.

There is a paucity of research examining public response to the cumulative effects of multiple related extreme events over time. We investigated the separate and combined effects of frequency and trajectory of terrorist attacks. A scenario simulation of a series of gas station bombings in Southern California was developed to evaluate respondents' affect, risk perception, and intended avoidance behavior using a 3 (frequency; low vs. medium vs. high) by 3 (trajectory; increasing vs. constant vs. decreasing) factorial design. For each of the nine conditions, three videos were created to simulate news broadcasts documenting the attacks over a three-week period. A total of 275 respondents were included in the analysis. Results from analysis of covariances (ANCOVAs) indicate that trajectory of the sequential attacks (increasing or decreasing in frequency) predicts negative affect, risk perception, and avoidance behavior. In contrast, frequency predicts neither negative affect, positive affect, risk perception, nor intended avoidance behavior. Results from structural equation modeling (SEM) further indicate that the effect of negative affect on behavioral intention is mediated by risk perception and the effect of trajectory on risk perception is partially mediated by negative affect. In addition, both ANCOVAs and SEM model results suggest that (1) females experience less positive affect and perceive more risk than males, (2) respondents with higher income perceive more risk, and (3) younger respondents are more likely to modify their behavior to avoid the risk of future attacks.