Relationship between suboptimal cognitive effort and the clinical scales of the Personality Assessment Inventory

Abstract

Little research has examined the relationship between the Personality Assessment Inventory (PAI) and cognitive effort. The current study extends the research on personality assessment and suboptimal cognitive effort by evaluating the relationship between the PAI clinical scales and the Test of Memory Malingering (TOMM) in a neuropsychological population. Utilizing corrections for multiple comparisons, rank-order correlations with the TOMM Trial 2 (T2) and the PAI clinical scales indicated a significant relationship with the SOM (rho = −.26, p <.001), with additional scales (SCZ, ANX, and DEP) trending toward significance. Analysis of SOM subscales indicated a significant relationship between SOM-C and T2 as well. To further explore the relationship between SOM and the TOMM, ANOVA results indicated that individuals scoring within normal limits on the SOM had higher mean TOMM scores than those with extremely elevated SOM. Additional analyses indicated that utilizing the cut-off for extreme responding on the SOM scale (T > 87) had adequate sensitivity (93%) and specificity (76%) in predicting TOMM performance, with a positive predictive power of 54% and a negative predictive power of 97%, resulting in a 91% correct classification rate. Thus, the evidence suggests that extreme scores on SOM should prompt careful evaluation for suboptimal cognitive effort.

Keywords:

• Personality Assessment Inventory
• Test of Memory Malingering
• Cognitive effort

Notes

¹ One issue not directly addressed in the current analysis is the relationship between the validity scales, SOM, and suboptimal effort. Previous research by the first author (Whiteside et al., 2009) found that the Negative Impression Management (NIM) validity scale was the best predictor of cognitive effort among the PAI validity scales. To address the issue of the incremental validity of SOM and its subscales over the use of the traditional PAI validity scales alone (especially NIM), partial correlations between SOM, its subscales, and the TOMM were calculated. In the partial correlations there were still small but statistically significant correlations between the SOM scale (r = −.13, p <.05) and the SOM-C subscale (r = −.14, p <.05) when accounting for the variance from NIM. The other subscales did not have a significant relationship. Thus, these results indicate evidence for some incremental validity when the SOM and SOM-C are used in combination with the traditional validity scales (especially in combination with NIM). In other words, SOM and SOM-C offer additional data on suboptimal effort, although only as a supplement to and in conjunction with PAI validity scales like NIM. Thus the results suggest that clinicians could use extreme elevations on several PAI scales, particularly NIM, SOM, and SOM-C as indicators of an increased risk of suboptimal cognitive effort.