Assessing dissimulation and denial on the MMPI in a sample of maximum security, male inmates

Comparisons were made between three groups of maximum security inmates thought to possess varying degrees of motivation to either exaggerate or suppress psychiatric symptomatology in their Minnesota Multiphasic Personality Inventory (MMPI) self-report. A group of individuals requesting single-cell placement (the group hypothesized to be motivated to exaggerate symptomatology) were found to score significantly higher on Scale F, the F-K Index, and a number of special MMPI scales (i.e., D-O, Hy-O, Pd-O, Pa-O, Ma-O, Dissimulation Scale, total number of Obvious Items, O:S Ratio) and significantly lower on scales K, Hy-S, Ma-S, and the total number of Subtle items relative to inmates undergoing parole evaluations (denial condition) or entering group therapy (neutral condition). Differences between the parole and group therapy conditions were relatively small, with only D-O, Hy-O, and the Dissimulation Scale producing statistically significant results. These findings tend to support use of the MMPI in assessing a respondent's test-taking attitude, particularly in cases where the subject is attempting to exaggerate psychiatric symptomatology.