The Effect of Everyday Safety Behavior on Intolerance of Uncertainty and Indecisiveness

Background: Intolerance of Uncertainty (IU) is a transdiagnostic risk factor for mental disorders. It also contributes to indecisiveness. IU-related safety behaviors (IUSB) may reinforce IU and associated constructs like indecisiveness. Two pre-registered experiments tested whether increasing IUSB would lead to higher increases in IU and more indecisiveness.Methods: In Study 1 (N = 99), participants were instructed to either engage in more IUSB for one week (Increase condition), or to merely report their unchanged IUSB ( control condition). Study 2 (N = 147) replicated the procedure, but with a decreased IUSB condition instead of the control condition. In both studies, IU was measured pre- and post-manipulation, and (state) indecisiveness was assessed post-manipulation referring to a realistic decision. Results: Regarding preregistered analyses alone, hypotheses were not supported. IU increased across both conditions in Study 1, while Study 2 showed a general decrease, independent of condition. Indecisiveness was unaffected by the manipulation. However, exploratory mediation analyses in both studies suggested that the condition with increased IUSB did result in more IU indirectly through IUSB. The manipulation check revealed that, although the most IUSB was always found in the intended (i.e., the Increase) condition, inducing more IUSB relative to baseline was unsuccessful. Conclusions: While the immediate effects of increasing IUSB on IU and indecisiveness were not supported, mediation findings provide preliminary evidence for a causal link between IUSB and IU. Future research should refine methods to better manipulate IUSB and further investigate its role in maintaining IU, which may have implications for IU-centered interventions.