Are findings on uncertainty transferable to indecisiveness? – Conceptual relationships, critical boundary conditions, and implications for application

• Applicant: Professor Dr. Alexander L. Gerlach, since 1/2020
• Subject Area: Social Psychology, Industrial and Organisational Psychology ; Personality Psychology, Clinical and Medical Psychology, Methodology
• Term: from 2019 to 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 427465870

• Final Report Year: 2025

Final Report Abstract

Indecisiveness means that a person has difficulty making choices across different situations. This can significantly impact daily life in a world filled with complex decisions and is often observed in psychological disorders such as anxiety or obsessive-compulsive disorder. One key explanatory approach for indecisiveness is intolerance of uncertainty (IU)—the inability to cope with uncertainty. Since many decisions involve uncertainty, individuals with high IU struggle to commit to a choice. As a result, they try to minimize uncertainty as much as possible. However, this very behavior makes decision-making more difficult and may even reinforce IU in the long run. This research project aimed to address the following questions: 1. Is IU a causal factor in indecisiveness? 2. Is IU linked to dysfunctional uncertainty reduction? 3. Do such uncertainty reduction strategies reinforce IU and indecisiveness? Several studies were conducted: Study 1 found that indecisiveness was more strongly associated with IU when the decision was important. Study 2 demonstrated that IU is linked to problematic safety behaviors in decision-making situations, such as excessive research. Studies 3a–c replicated this association in various decision-making scenarios. A mediation effect via indecisiveness was found, but decision importance did not amplify this effect. Study 4 examined behavioral uncertainty reduction but found no link between IU and actual information gathering. Study 5 provided the first causal evidence that increasing IU leads to greater indecisiveness. Studies 6a & 6b found partial evidence that excessive safety behavior reinforces IU. Study 7 (EMA study in daily life) confirmed that IU is associated with indecisiveness and problematic safety behaviors in real-world decisions. Studies 8a-c examined central relationships in a clinical sample with anxiety or obsessive-compulsive disorders, which emphasizes the clinical relevance. IU was experimentally influenced and had an indirect effect on indecisiveness. IU was also in part related to behavioral indicators of uncertainty reduction. IU is consistently linked to indecisiveness and problematic uncertainty reduction. IU causes indecisiveness, while safety behaviors can reinforce IU. These mechanisms mirror those observed in anxiety and obsessive-compulsive disorders. The findings provide valuable insights for interventions aimed at reducing IU and indecisiveness in both clinical and non-clinical contexts.

Publications

• Too much at stake – Testing when intolerance of uncertainty predicts indecisiveness. 38th Symposium Clinical Psychology and Psychotherapy, Mannheim, Germany
  Appel, H. & Gerlach, A. L.
  
• Too much at stake – Testing when intolerance of uncertainty predicts indecisiveness. 51st EABCT Annual Conference, Belfast, Ireland
  Appel, H. & Gerlach, A. L.
  
• Making it worse by trying to make it better – Intolerance of uncertainty is associated with maladaptive safety behavior in decision making. 52nd EABCT Annual Conference, Barcelona, Spain
  Appel, H. & Gerlach, A. L.
  
• Systematic Search and Scoping Review of Physicians’ Intolerance of Uncertainty and Medical Decision-Making Uncertainties During the COVID-19 Pandemic: A Summary of the Literature and Directions for Future Research. Journal of Clinical Psychology in Medical Settings, 31(2), 338-358.
  Appel, Helmut & Sanatkar, Samineh
  
• Und täglich grüßt die Entscheidungsschwäche – Unsicherheitsintoleranz und Sicherheitsverhalten in einer Experience Sampling-Studie zu Entscheidungen im Alltag. 2. Deutscher Psychotherapiekongress, Berlin, Germany
  Appel, H., Krasko, J., Luhmann, M. & Gerlach, A. L.
  
• Checking the Uncertain. Zeitschrift für Klinische Psychologie und Psychotherapie, 53(3), 109-118.
  Hülsdonk, Amrei; Pohl, Anna; Appel, Helmut & Wolters, Carolin
  
• Intolerance of uncertainty predicts indecisiveness and safety behavior in real-life decision making: Results from an experience sampling study. Journal of Research in Personality, 110, 104490.
  Appel, Helmut; Krasko, Julia; Luhmann, Maike & Gerlach, Alexander L.
  
• Intolerance of uncertainty causally affects indecisiveness. British Journal of Clinical Psychology, 64(3), 806-816.
  Appel, Helmut & Gerlach, Alexander L.