Differentiating violent and nonviolent opiate-addicted reformatory inmates with the MMPI

Used multivariate profile analysis and stepwise discriminant analysis in an effort to discriminate among four groups of male opiate-addicted reformatory inmates (N = 193) classified according to degree of criminal violence: (1) Bodily Violent (N = 19); (2) Potentially Bodily Violent (N = 25); (3) Materially Violent (N = 113); and (4) Nonviolent (N = 36). Profile analysis indicated that the four groups were very similar; a stepwise discriminant analysis significantly distinguished the Bodily Violent group from each of the other groups, but failed to differentiate successfully among the remaining three groups. A second stepwise discriminant analysis, in which Groups 2, 3 and 4 were combined, produced a significant discriminant function and correctly classified 68.4% of the Bodily Violent group and 75.9% of the combined Nonbodily Violent groups. The MMPI scales that contributed most to the latter prediction of group membership, in relative order of discriminating power, were: F, MA, D, PD, HS, PA and SI.