An item response theory analysis of the Carver and White (1994) BIS/BAS Scales

The Carver and White BIS/BAS Scales comprise a scale for measuring behavioural inhibition sensitivity and three scales for measuring the behavioural activation sensitivity factors of reward responsiveness, drive and fun seeking. Item response theory (IRT), using Samejima's (1969) graded response model, was used to examine the psychometric properties of these four scales. A total of 520 adult participants completed the BIS/BAS Scales. Although all items in all four scales were reasonably effective in discriminating their respective traits, they provided good measures of their respective latent traits from only moderately low to moderately high trait levels. Also, the category response curves for the first three of the four response options for the items in the reward responsiveness scale showed considerable overlap. These findings suggest some limitations in the psychometric qualities of the BIS/BAS Scale.