Abstract
Following the judicial principles of good faith and rationality, an MMPI index (F + Pd + Ma) was selected for attempted validation in a law enforcement job context. Disciplinary suspension days after three year careers provided a criterion of job misperformance for 107 officers hired consecutively into a police department. Preemployment MMPIs were scored for the index, which has previously been proposed in a clinical psychology context as a measure of aggression. Each component of the index had been found to be related to some aspect of job misperformance in other studies. A statistically significant correlation of .223 was found. Analysis with a Receiver Operator Characteristic procedure located an optimal cutoff score of 192. A statistically significant Wilcoxon Statistic of .654 describes the effectiveness of the cutoff in differentiating the most extreme 10% of the officers from the remaining pool. Sensitivity of the index at 192 is .455; specificity is .854. Further construct validation is necessary to determine if the index measures potential for aggression or some other attribute of personality. Judicial decisions regarding the use of psychological tests and clinical judgment in occupational settings are reviewed.