Temporal Stability of the Personality Assessment Inventory: Investigating Potential Predictors

In this study, we explored the temporal stability of the Personality Assessment Inventory (PAI), which has not been comprehensively reexamined since it was first published. Our three specific aims were to determine the utility of PAI indicators of basic protocol validity (inconsistent responses [ICN] and highly unusual/unlikely responses [INF]) in identifying suspect responding; calculate the stability coefficients for each PAI scale and subscale across 3-, 6-, and 9-week spans; and explore whether profile stability across four measurements could be prospectively predicted. We administered the PAI to a sample of undergraduates (N = 579) at four separate timepoints. ICN and INF effectively identified likely attriters and inconsistent responders. All PAI full scales and subscales evidenced good test-retest reliability, with some small exceptions. Finally, all PAI clinical scales were correlated with profile instability although many of these correlations were no longer significant when controlling for mean clinical elevation of the profile. We interpreted these results as evidence for the utility of PAI validity scales, the temporal reliability of the PAI, and the role of psychopathology in response variability over time. We also discussed some preliminary evidence that this variability can be prospectively predicted, suggesting that it in part reflects substantive changes rather than random error variance.