Differentiating violent and nonviolent prison inmates by use of selected MMPI scales.

Used multivariate procedures to determine whether prisoners who committed violent acts while in prison could be differentiated from those who did not. Ss were 141 adult male inmates in maximum security prisons. Multiple variable profile analysis that employed 22 MMPI scales and four demographic items significantly differentiated between violet and nonviolent inmates. Discriminant analysis that used all 26 variables yielded a significant root that accounted for 34.9% of the variance between violent and nonviolent inmates. The MMPI scales that contributed most to prediction of group membership were F, PA, PT, and SC, all of which had discriminant load values above .40. Finally, a discriminant function prediction equation was derived to predict the criterion variable (violent or nonviolent behavior). Applying this equation without knowledge of the S's actual group membership correctly classified 72.9% of the violent and 80.6% of the nonviolent inmates.

Frequency of MMPI two-point codes in a large alcoholic sample.

The MMPI two-point codes of 1,009 male Caucasian inpatient alcoholics were examined. Although the mean profile was 4-2, analysis of individual profiles revealed that 79% of the profiles were classified differently from the mean profile. These findings indicate that alcoholics are a heterogeneous group with respect to the MMPI. Some of the most frequently occurring codetypes seem to be associated with widely different behavioral descriptions, which leads to the inference that alcoholics are heterogeneous with respect to personality characteristics as well.

A comparison of classification rates of the original and revised Marks and Seeman rules.

The Marks and Seeman rules for profile classification were compared with revised rules. The rate of classification on a large sample of psychiatric profiles was 16.88% for the original rules and 49.72% with the revised rules. The revised rules will make the codebook applicable to more cases.