A revised model of Dickman's dysfunctional impulsivity scale

The literature suggests limitations to Dickman's dysfunctional impulsivity (DI) scale. These concerns are centered on the measurement properties of this scale and on its reliance on student samples. To address these criticisms, the DI was administered to a random adult sample (n = 649, mean age 43.83 ± 13.46 years), 13% of whom were university educated. Confirmatory factor analysis (CFA) did not support the fit of the posited 12-item DI scale. The full sample was randomly divided. Principal components analysis was applied to one sample (n = 328), resulting in a 9-item model. This new model was then replicated using CFA in the second sample (n = 321). Cronbach’s α for the 9-item model was 0.84 and item-total correlations were > 0.39. The 30th and 70th percentile scores from the DI distribution of scores were used to categorize participants with low and high DI. The high-DI group was associated with significantly more driving distractions and lane crossings.