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P. A. Arbisi and Y. S. Ben-Porath (1995) originally proposed that the Infrequency Psychopathology scale, F(p), be used as the final step in an algorithm to determine the validity of a Minnesota Multiphasic Personality Inventory-2 (MMPI-2) protocol. The current study used taxometric procedures to determine the latent structure of F(p) among examinees with profiles that would necessitate the interpretation of F(p) when using Arbisi and Ben-Porath's proposed algorithm. Participants included a subsample of 289 consecutively referred pretrial forensic examinees adjudicated incompetent to stand trial with high Infrequency (F) scale scores, thereby providing a sample that would be expected to have a high base rate of persons with bona fide psychopathology and persons with incentive to overreport psychopathology. Using MAMBAC and MAXEIG, F(p) produced a taxonic latent structure within the subgroup of examinees who obtained raw scores on F of greater than 17. These results support Arbisi and Ben-Porath's original proposal to use F(p) to identify a distinct subgroup of overreported MMPI-2 protocols within forensic psychiatric examinees with high elevations on F. Implications and suggestions for future research are provided.

The comparability of the MMPI-2 in American Indians with the MMPI-2 normative group was investigated in a sample of 535 Southwestern and 297 Plains American Indian tribal members with contrasting sociocultural and historical origins. Both American Indian tribal groups had clinically significant higher T scores (> 5 T points) on 5 validity and clinical scales, 6 content scales, and 2 supplementary scales than did the MMPI-2 normative group. There were no significant differences between the 2 tribal groups on any of the MMPI-2 clinical, content, or supplementary scales. Matching members of both tribes with persons in the MMPI-2 normative group on the basis of age, gender, and education reduced the magnitude of the differences between the 2 groups on all of these scales, although the differences in T scores still exceeded 5 T points. It appears likely that the MMPI-2 differences of these 2 American Indian groups from the normative group may reflect their adverse historical, social, and economic conditions.

R. W. Robin, R. L. Greene, B. Albaugh, A. Caldwell, and D. Goldman (2003) reported that members of 2 American Indian tribal groups had statistically significant higher T scores on several MMPI-2 clinical, content, and supplementary scales than did the MMPI-2 normative group. The present study investigated the empirical correlates of the MMPI-2 scales in these American Indian tribal members. There were a large number of significant correlates reflecting antisocial symptoms with Scales 4 (Psychopathic Deviate), 9 (Hypomania), Anger, and Antisocial Practices. There were even a larger number of significant correlates reflecting generalized distress and negative affect with Scales 7 (Psychosthenia), 8 (Schizophrenia), Anxiety, Obsessions, Depression, and Welsh Anxiety. The rationally derived MMPI-2 content scales generally had larger correlations with these constructs than the clinical scales. Thus, the differences reported by R. W. Robin et al. (2003), appear to reflect behaviors and symptoms that American Indians participants were experiencing rather than test bias.

Data from several clinical samples and the Minnesota Multiphasic Personality Inventory--2 standardization group are presented to familiarize the reader with response patterns of different groups on a new validity scale designed to assist in the identification of exaggeration or fabrication of psychological disturbance. Sensitivity-specificity analyses are included along with suggestions for use of the F(p) Scale with other validity scales. Cautions about setting single cutoff scores are also discussed.

The typology of overreporting, which is a deliberate attempt to amplify symptoms, simulate psychopathology, or understate coping capacities, was examined using taxometric procedures with Minnesota Multiphasic Personality Inventory-2 (MMPI-2) Infrequency scales [F and F(p)] in psychiatric inpatient and Veterans Affairs (VA) medical center treatment settings. Overreporting was identified as a taxon using several taxometric procedures, and the multiple estimates of the taxon base rate were consistent within each sample. Mean base-rate estimates were .27 and .19 for the psychiatric inpatient and VA medical center settings, respectively. Overall classification rates ranged from .80 to .97 across the 2 settings, which supports the use of F and F(p) in the identification of overreporting on the MMPI-2 in psychiatric inpatient and VA medical center settings.