Minnesota Multiphasic Personality Inventory

The Minnesota Multiphasic Personality Inventory (MMPI) is a standardized psychometric test of adult personality and psychopathology. A version for adolescents also exists, the MMPI-A, and was first published in 1992. Psychologists use various versions of the MMPI to help develop treatment plans, assist with differential diagnosis, help answer legal questions (forensic psychology), screen job candidates during the personnel selection process, or as part of a therapeutic assessment procedure.

The original MMPI was developed by Starke R. Hathaway and J. C. McKinley, faculty of the University of Minnesota, and first published by the University of Minnesota Press in 1943. It was replaced by an updated version, the MMPI-2, in 1989 (Butcher, Dahlstrom, Graham, Tellegen, and Kaemmer). An alternative version of the test, the MMPI-2 Restructured Form (MMPI-2-RF), published in 2008, retains some aspects of the traditional MMPI assessment strategy, but adopts a different theoretical approach to personality test development. The newest version (MMPI-3) was released in 2020.

The original authors of the MMPI were American psychologist Starke R. Hathaway and American neurologist J. C. McKinley. The MMPI is copyrighted by the University of Minnesota.

The MMPI was designed as an adult measure of psychopathology and personality structure in 1939. Many additions and changes to the measure have been made over time to improve interpretability of the original clinical scales. Additionally, there have been changes in the number of items in the measure, and other adjustments which reflect its current use as a tool towards modern psychopathy and personality disorders. The most historically significant developmental changes include:

The MMPI-2-RF is a streamlined measure. Retaining only 338 of the original 567 items, its hierarchical scale structure provides non-redundant information across 51 scales that are easily interpretable. Validity scales were retained (revised), two new validity scales have been added (Fs in 2008 and RBS in 2011), and there are new scales that capture somatic complaints. All of the MMPI-2-RF's scales demonstrate either increased or equivalent construct and criterion validity compared to their MMPI-2 counterparts.

Current versions of the test (MMPI-2 and MMPI-2-RF) can be completed on optical scan forms or administered directly to individuals on the computer. The MMPI-2 can generate a Score Report or an Extended Score Report, which includes the Restructured Clinical scales from which the Restructured Form was later developed. The MMPI-2 Extended Score Report includes scores on the original clinical scales as well as Content, Supplementary, and other subscales of potential interest to clinicians. Additionally, the MMPI-2-RF computer scoring offers an option for the administrator to select a specific reference group with which to contrast and compare an individual's obtained scores; comparison groups include clinical, non-clinical, medical, forensic, and pre-employment settings, to name a few. The newest version of the Pearson Q-Local computer scoring program offers the option of converting MMPI-2 data into MMPI-2-RF reports as well as numerous other new features. Use of the MMPI is tightly controlled. Any clinician using the MMPI is required to meet specific test publisher requirements in terms of training and experience, must pay for all administration materials including the annual computer scoring license and is charged for each report generated by computer.

In 2018, the University of Minnesota Press commissioned development of the MMPI-3, which was to be based in part on the MMPI-2-RF and include updated normative data. It was published in December 2020.

The original MMPI was developed on a scale-by-scale basis in the late 1930s and early 1940s. Hathaway and McKinley used an empirical [criterion] keying approach, with clinical scales derived by selecting items that were endorsed by patients known to have been diagnosed with certain pathologies. The difference between this approach and other test development strategies used around that time was that it was in many ways atheoretical (not based on any particular theory) and thus the initial test was not aligned with the prevailing psychodynamic theories. Theory in some ways affected the development process, if only because the candidate test items and patient groups on which scales were developed were affected by prevailing personality and psychopathological theories of the time. The approach to MMPI development ostensibly enabled the test to capture aspects of human psychopathology that were recognizable and meaningful, despite changes in clinical theories. However, the MMPI had flaws of validity that were soon apparent and could not be overlooked indefinitely. The control group for its original testing consisted of a small number of individuals, mostly young, white, and married men and women from rural areas of the Midwest. (The racial makeup of the respondents reflected the ethnic makeup of that time and place.) The MMPI also faced problems as to its terminology and its irrelevance to the population that the test was intended to measure. It became necessary for the MMPI to measure a more diverse number of potential mental health problems, such as "suicidal tendencies, drug abuse, and treatment-related behaviors."