A re-examination of the BIS/BAS scales: Evidence for BIS and BAS as unidimensional scales.

Abstract

Carver and White's behavioral inhibition system and behavioral activation system (BIS/BAS) scales are the most widely used to assess constructs of the revised reinforcement sensitivity theory. This study provides a re-examination of the latent structure of the original BIS/BAS scales. The interpretability of the three purported BAS subfactors relative to a "general behavioral activation" factor was assessed using Schmid-Leiman and standard confirmatory factor analysis. Regarding the BIS scale, comparisons were made between (a) Carver and White's unidimensional BIS model, (b) Johnson, Turner, and Iwata's 2-factor BIS model, (c) Heym, Ferguson, and Lawrence's alternative 2-factor BIS model, and (d) a modified Heym et al. model (unidimensional) controlling for method effects of reverse-scored items. Results revealed the majority of variance of individual BAS items was accounted for by a common, general BAS dimension. Additionally, for the BIS scale, results of the χ2 difference statistical test supporting the 1-factor model, as well as the noted theoretical and psychometric difficulties in interpreting a multifactor BIS scale, provide converging support that BIS items actually represent a single, unidimensional factor. The collective results suggested that the BIS and BAS scales should be conceptualized as separate unidimensional measures, which is consistent with theory behind the original development.