Psychometric Analysis and Tentative Shortening of Survey of Personal Beliefs

The Survey of Personal Beliefs (SPB) is a frequently used measure of irrational beliefs, but can display less than ideal psychometric properties. In the first study of the present project, the five subscales of the SPB correlated as expected with higher levels of perfectionism, shame, and guilt. A confirmatory factor analysis, nevertheless, revealed that these subscales did not adequately describe responding on the SPB, and internal reliability for some subscales was poor. An abbreviated 12-item version of the SPB was more reliable than the subscales and generally as valid as the full 50-item instrument. With a second data set, the shortened version of the SPB was more consistent than the full 50-item scale in correlating positively with at least some measures of maladjustment that included depression, anxiety, neuroticism, and alexithymia. Future researchers may want to utilize the shorter 12-item version of the SPB as a more convenient and psychometrically acceptable measure of irrational beliefs.