(Hu)man versus mean revisited: MMPI group data and psychiatric diagnosis.

A meta-analysis of Minnesota Multiphasic Personality Inventory (MMPI) data from 403 control and psychiatric samples was used to (a) examine demographics associated with previously published MMPI studies, (b) test Goldberg's (1972) indexes for predicting normal versus deviant and neurotic versus psychotic group membership, (c) compare multiple regression, discriminant function, and logistic regression analyses commonly used to study the relation between the MMPI and diagnostic group membership, and (d) examine the signal within the MMPI as it relates to current psychiatric diagnosis. Group data were found to be efficient indicators of the relation between the MMPI and diagnosis, although efficiency is compromised by within-sample heterogeneity. The 3 statistical methods examined obtained equivalent results. Regression models related to group prediction are presented.