Fearing the unknown: a short version of the Intolerance of Uncertainty Scale

J Anxiety Disord. 2007;21(1):105-17. doi: 10.1016/j.janxdis.2006.03.014. Epub 2006 May 2.


Intolerance of uncertainty is the tendency of an individual to consider the possibility of a negative event occurring unacceptable, irrespective of the probability of occurrence. It is a key component of worry, state anxiety, and related anxiety pathologies. The 27-item Intolerance of Uncertainty Scale (IUS) was developed to measure intolerance of uncertainty. Previous psychometric analyses of the IUS have suggested both four- and five-factor models. High inter-item correlations, factor instability, and previous theoretical research support the development of a reduced measure. The present study used two undergraduate samples and evaluated a psychometrically stable 12-item two-factor version of the IUS. The reduced measure (IUS-12) retained exemplary internal consistency, while correlating extremely well with the original IUS and related measures of anxiety and worry. The IUS-12 also demonstrated a stable two-factor structure, representing both anxious and avoidance components of intolerance of uncertainty. Directions for future research and potential applications for assessment are discussed.

Publication types

  • Validation Study

MeSH terms

  • Adolescent
  • Adult
  • Anxiety / diagnosis
  • Attitude*
  • Cognition*
  • Escape Reaction*
  • Fear*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Reproducibility of Results
  • Surveys and Questionnaires*