The Minnesota Multiphasic Personality Inventory-2 (MMPI-2)

Minnesota Multiphasic Personality Inventory-2The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is a 567-item, true-or-false measure of personality and psychological symptoms. It can be administered individually or in a group format, via booklet or on a computer. It requires roughly a sixth-grade reading level. Audiocassette versions are available for individuals with reading difficulties, vision problems, or physical disabilities that affect their abilities to manipulate the test materials. It is intended for individuals age 18 or older; an adolescent form (the MMPI-A) is available for individuals between the age of 14 and 18. Under standard conditions, the MMPI-2 requires approximately 60 to 90 minutes to complete. It can be scored by hand, optical scanner, or computer processing. Computer-based interpretations of the results are available as well. Nonetheless, MMPI-2 results should be interpreted only by individuals who are thoroughly trained in test theory, personality, psychopathology, and psychodiagnosis.

Development of the MMPI

The original version of the instrument, the MMPI, was published in 1943. It had been developed at the University of Minnesota by psychologist Starke Hathaway and psychiatrist J. Charnley McKinley to aid in the diagnostic screening of clinic patients. The original items were selected for the inventory because they discriminated statistically between psychiatric patients and individuals without identified psychiatric problems. This method of test construction, known as empirical keying, reduced the subjectivity of the interpretation of the test results.

Initially, the inventory included eight clinical scales, which measured psychoneurotic concern with bodily health (Hypochondriasis, now known as Scale 1); symptomatic depression (Depression, Scale 2); conversion hysteria (Hysteria, Scale 3); antisocial tendencies and psychopathic behavior (Psychopathic Deviate, Scale 4); suspiciousness and mistrust (Paranoia, Scale 6); anxiety with obsessive and compulsive features (Psychasthenia, Scale 7); symptoms of the four recognized subtypes of schizophrenia (Schizophrenia, Scale 8); and the tendency to act in euphoric and hyperactive ways (Hypomania, Scale 9). Two more scales were later developed from the items, at the time being intended to measure “male sexual inversion” or homosexuality (Masculinity-Femininity, Scale 5) and social introversion-extroversion (Social Introversion, Scale 0).

In addition, four scales were created to evaluate the validity of the test taker’s report: Cannot Say (?), to track the number of items that were omitted or to which both true and false were answered; Lie (L), to detect unsophisticated attempts to portray oneself overly favorably; Infrequency (F), to reflect item responses that deviated from typical ones; and Correction (K), to measure clinical defensiveness. The K scale was later used to weight scores on Scales 1,4, 7, 8, and 9, which were thought to be most susceptible to underestimation in the context of a defensive test-taking approach. Evaluating the validity of respondents’ profiles is critical for understanding their degree of cooperation with the assessment process and their possible attempts to distort responses, such as by minimizing problems or exaggerating symptoms.

In the years following the publication of the MMPI, it was subjected to extensive and rigorous scientific study. The research showed that the instrument was not reliable for differentially diagnosing discrete psychiatric groups, as it was originally intended to do. However, the research produced a collection of empirical correlates of high and low scores on the clinical scales and corresponding classification rules for describing behavior and personality traits. Over time, the MMPI became the most widely used personality instrument in the United States, and the MMPI-2 holds that same designation today.

The MMPI-2

In 1982, a committee was formed to modify the original test booklet and develop new norms for the MMPI. The restandardization project was initiated because (a) many of the 40-year-old MMPI items were out-of-date, and some were objectionable in content; and (b) the original normative sample of White, rural Minnesotans was not regarded as representative of the U.S. population in the late twentieth century. In 1989, the restandardization project culminated in the publication of the MMPI-2. Extensive validation research has documented the MMPI-2 as an effective replacement for the original MMPI for assessing adults.

The MMPI-2 contains the same clinical scales and validity indicators as the original instrument. However, there have been changes in the interpretation of some scales (for example, Scale 5 is now considered a measure of degree of deviation from stereotypical gender roles). There also are several new validity indicators, including two additional scales of infrequent responses (FB, measuring endorsement of aberrant items in the latter portion of the test; and F(p), measuring endorsement of problems that are uncommon even among psychiatric inpatients); two response-inconsistency scales (Variable Response Inconsistency, or VRIN, and True Response Inconsistency, or TRIN); and means of assessing “faking good” among nonclinical samples (such as Superlative, or S). Awareness of the benefits of paying attention to the content of the inventory items prompted the development of clinical scale subscales, so-called content scales, and myriad supplementary scales. Most recently, a set of restructured clinical scales has been introduced and proposed as another means of facilitating profile interpretation.

The MMPI-2 can be used in a variety of settings. It is valuable for assessing psychiatric inpatients and outpatients, and it is also favored for use in forensic settings. It provides important information for non-clinical purposes as well, including screening for high-risk employment positions in the airline industry and public safety. It is valid for use with people representing a range of ethnic and cultural backgrounds, and it has been translated into dozens of foreign languages to extend its usefulness beyond English-speaking populations. Serving as a rich source for empirical investigation, its body of literature is ever increasing. Potential new and advanced uses include computerized adaptive testing to tailor the instrument to the individual while it is being taken. Numerous texts and other reference materials provide further information about these innovations (as well as about useful interpretation strategies), and frequent national workshops and conferences afford training opportunities and expose attendees to the latest research on the MMPI-2 and its applicability.

The MMPI-2 can add to evaluation in career counseling assessments in several ways. First, the MMPI-2 item pool contains many items that address the assessment of emotional adjustment, a factor that is pertinent to many careers that require high emotional stability and good judgment (for example, in airline pilot selection, nuclear power plant operation, police and fire departments). The test also provides information about a potential candidate’s general personality functioning, including factors such as interpersonal relationships, impulse control, responsibility, and potential substance use problems. The MMPI-2 is one of the widely used personality measures in personnel selection and can add valuable information to the decision as to whether a client shows the emotional stability and responsibility needed for some occupations.

See also:

References:

  1. Butcher, J. N. 2005. MMPI-2: A Beginner’s Guide. 2d ed. Washington DC: American Psychological Association.
  2. Graham, J. R. 2000. The MMPI A Practical Guide. 3d ed. New York: Oxford University Press.