Investigating the conditional effects of action versus inaction decisions on regret.

This research posits that when people, who make a proactive choice for a justified reason, encounter an interim negative outcome (e.g., a temporary loss from a stock investment that could yield a profit in the future), they engage in the self-justification mechanism to view their decision more favorably, initiate self-serving bias to minimize self-blame for the outcome, and trigger confirmatory bias to interpret the outcome favorably. Therefore, individuals who are responsible for switching a course (action decision), or choosing not to switch a course (inaction decision), for a justified reason minimize self-blame and reduce counterfactual thinking, ultimately leading to lower regret for negative interim outcomes than individuals with no-decision responsibility. Furthermore, this research suggests that when a negative outcome is terminal (e.g., end-of-the-semester final grade in a course) or the foregone option is superior, this mitigating effect on regret is minimized and moderated. Nine studies, including two replication studies reported in the Supplemental Material, document the conditional effects and show that decision justification reduces regret; however, people experience more regret from counterfactual thinking about imaginary alternatives than from self-blame. The studies also suggest that action decisions are not more abnormal than inaction decisions, because they elicit the same level of decision responsibility and control to affect downstream constructs, including justification, counterfactual thinking, self-blame, and regret, equivalently. Overall, this research clarifies various constructs associated with responsibility, refines our understanding of the relationship between decision responsibility and regret, and deepens insights into the psychology of regret. (PsycInfo Database Record (c) 2026 APA, all rights reserved).