Using item response theory to examine the White Bear Suppression Inventory

The White Bear Suppression Inventory (WBSI; Wegner & Zanakos, 1994) was designed to assess thought suppression as a dispositional characteristic. Researchers examining the WBSI have found support for a unidimensional construct although multi-dimensional factorial solutions have been suggested. In the current study, we used item response models to examine the primary factor underlying the WBSI. Item response analyses suggested significant overlap in information provided by WBSI items. Six of the 15 items were identified as providing unique information about individual levels of latent thought suppression and were determined to provide good discrimination across varying levels of the trait. When compared to the full WBSI, the six-item index of thought suppression retained almost identical correlations to measures of worry, emotional avoidance and depression. Implications for the assessment of thought suppression as an individual difference variable are discussed.