MMPI-2 Normative Data for the F-K Index: Implications for Clinical Neuropsychological, and Forensic Practice

Abstract

The F-K index has long been used as a validity indicator with the MMPI to help identify subjects who may be over- or underreporting psychological problems. The revision of the MMPI necessitates the collection of new norms and development of cutoff scores for the F-K index due to changes in the test itself as well as changes in the way subjects respond to items since the time of the development of the original test. Continuation of the use of old cutoff scores and clinical lore may lead to erroneous conclusions and decisions in the clinical and forensic arenas in which the index is used. MMPI-2 norms for the F-K index are provided for the standardization sample, and additional data are presented for samples of psychiatric patients, head injured patients, individuals seeking disability benefits, job applicants for police and priest positions, and substance abusers. Implications for use of the tables for interpretation of F-K scores are discussed.

Comparison of MMPI—2 responses of child custody and personal injury litigants.

“…They also question the applicability of such research to real-life situations in which, for example, convicted felons are seeking release from prison, applicants are competing for a job, or parents are vying for custody of their children. The incentives in these situations are clearly hard to reproduce in analog research, although one recent study demonstrated that coached participants were more successful than uncoached participants in mimicking head injury problems on the MMPI-2 (Lamb et al, 1994) , 2 The few studies in which real-life participants have been used to investigate the utility of the MMPI-2 validity scales to detect a positive response bias have demonstrated significant differences in the distribution of validity scores between underreporting and accurately responding groups (Bagby et al, 1994;Baer, Wetter, Berry, & Nichols, 1993;Rothke et al, 1994). In addition, there is some research to demonstrate differences in MMPI-2 clinical profiles of chronic pain litigants (Dush, Simons, Platt, Nation, & Ayers, 1994) versus closed-head-injury litigants (Dunn & Lees-Haley, 1995;Gass, 1991).…”

A New Index for the MMPI‐2 Test for Detecting Dissimulation in Forensic Evaluations: A Pilot Study

“…The MMPI‐2 features six validity scales, 10 basic scales (clinical), 15 content scales, and 15 supplementary scales . In addition, this study took into consideration the “F minus K” Index (Dissimulation Index) developed by Gough in 1947, which is universally considered to be a reliable instrument according to many authors , and the Superlative Scale , which is made up of 50 items aimed at exploring the person's tendency to report self‐attributes as extremely positive.…”

“…According to our hypothesis, Control Scales (i.e., L, F, K, F‐back, VRIN, and TRIN), some Clinical/Content Scales (i.e., 1‐Hs, 2‐D, 3‐Hy, 6‐Pa, 7‐Pt, 8‐Sc, 9‐Ma, ANX, ANG, and FAM), the Superlative Scale, and the F‐K index would have to provide the largest mean differences between forensic and nonforensic groups. This hypothesis was based on research regarding MMPI‐2 face and construct validities .…”

Comparison of MMPI-2 Validity Scales Among Compensation-Seeking Caucasian and Asian American Medical Patients

“…When racial or ethnic group membership was mentioned in some MMPI-2 reports (Lees-Haley, 1997;Strong, glassmire, Frederick, & greene, 2006;Sweet, Malina, & ecklund-Johnson, 2006), no analysis of racial factors was made. Nor was there any comparison of racial groups made in an evaluation of 291 disabilitybenefit applicants comprised of more than 65% african americans (Rothke et al, 1994).…”