Better Safe than Sorry: Precautionary Reasoning and Implied Dominance in Risky Decisions

In four studies, student and nonstudent participants evaluated the possible outcomes of binary decisions involving health, safety, and environmental risks (e.g., whether to issue a dam-failure evacuation order). Many participants indicated that false positives (e.g., evacuation, but no dam failure) were better than true negatives (e.g., no evacuation and no dam failure), thereby implying that an incorrect decision was better than a correct one, and that the more protective action dominated the less protective action. A common rationale for this response pattern was the precautionary maxim “Better safe than sorry.” Participants apparently evaluated outcomes partly on the basis of the decisions that might lead to them, in conflict with consequentialist decision models. Consistent with this explanation, the prevalence of implied dominance decreased substantially when the emphasis on decisions was reduced. These results demonstrate that initial preferences for decision alternatives can seriously bias the evaluation of consequences in risky high-stakes decisions.