The Cognitive Bias Scale (CBS) was recently developed for the PAI (see Gaasedelen et al., 2019). The rationale behind the CBS’s development was that the PAI lacked any over-reporting indicators which assessed cognitive performance, and other personality inventories (i.e., MMPI-2-RF and MMPI-3) had such measures (e.g., Response Bias Scale [RBS]). Using similar methodology that was utilized during the development of the RBS (items were identified based on failed PVT performance and then combined into a scale), Gaasedelen and colleagues created a new validity scale for the PAI using a mixed neuropsychological sample. Subsequently, Armistead-Jehle, Ingram, and Morris replicated the scale in a military sample. In both cases, CBS worked well for identifying those with concurrently failed PVT. Check out the link above to see the article by myself and Nicole Morris of the PATS lab.
Subsequently, Boress et al (2021) examined alternative formats to create the CBS scale using the same, mixed clinical sample of patients on which the original CBS was calculated. They created three distinct scales, called scale of scales (CBS-SOS) because of their use of scale T-scores rather than item-level responses. In their paper, the CBS-SOS each performed well and provided support for the scale level versions of the CBS (AUC ranging from .72 to .75 for CBS-SOS-1 to CBS-SOS-3, respectively).
CBS-SOS Calculation Formulas
CBS-SOS-1 = (NIM + SOM + DEP + ANX + SCZ + SUI) / 6
CBS-SOS-2 = [(NIM*.015246) + (SOM*.033504)+(ANX*.017804)+(DEP*.010947) + (SCZ*-.002386) + (SUI*-.006888)] / 6
CBS-SOS-3 = (NIM + SCZ + SOM-C + SOM-S + DEP-P + ANX-P + PAR-R) / 7
As a follow-up to their work, we once again examined these CBS derived values within a military sample and contrasted performance to the CBS scale (not done in the CBS-SOS validation paper). This work is being presented at this year’s National Academy of Neuropsychology (NAN) conference and is being written up for publication now [Click to Download the Poster]. Here is what we (Armistead, Ingram, & Morris) found:
- AUC values for each of the CBS-SOS scales (and CBS) approximated large effects and offered approximately the same overall AUC classification value (~.70),
- CBS is highly correlated with all forms of the CBS-SOS (.83 to .84)
- Mean differences are medium in effect (Cohen, 1988) for the CBS and CBS-SOS scales, with effects all ranging from .72 to .75 in magnitude. The CBS-SOS-1 and CBS-SOS-3 had mean differences which were clinically meaningful (i.e., T-score difference of 5+ points)
- Cut values are slightly different in a military sample than in the non-military mixed neuropsychological sample on which the CBS-SOS formats were initially validated. The sensitivity took the largest dive with values for CB-SOS1 and CB-SOS3 below .05 when specificity was set at a .90 threshold.