Minnesota Multiphasic Personality Inventory

The Minnesota Multiphasic Personality Inventory (MMPI) is one of the most common psychological tests administered. It provides a myriad of information from a clinical standpoint and is also used in screening some public service job applicants. The MMPI is an easily administered true/false test that only requires an 8th-grade reading level to understand. 

MMPI history and development

The original MMPI was developed in 1939 at the University of Minnesota hospital and normed on patients and their visitors. A primary problem quickly identified with this norm group was the highly limited demographic. The majority of the sampled group were young, white, and married. 

The MMPI-2 attempted to address the limitations of the demographic and it was normed with a sample group of around 2,600 people from across the United States that was more representative of the country’s demographics.

The norm group included individuals previously diagnosed with certain disorders, allowing the researchers to base the test in practice rather than the theoretical models of other personality assessments.

MMPI uses and adaptations

• The MMPI-2 is the standard adult version of the assessment and was released in 1989. It has 567 true/false questions and takes around 60 to 90 minutes to complete. It was updated to reflect more culturally diverse values as the 1942 version was outdated. 
• The MMPI-2-Retracted Form was published in 2008 for use with adults and is a shorter version of the MMPI-2. It has 338 true/false items and is expected to take about 40 to 50 minutes to complete.
• MMPI-Adolescent was adapted and released in 1992 for adolescents from 14 to 18 years old. The MMPI-A has 478 questions and takes about one hour to complete. A short version, the MMPI-A-RF, was released in 2016, has 241 questions and takes only about 25 to 45 minutes to finish. 
• The newest version, the MMPI-3 was released in 2020. It has 335 questions and takes anywhere from 25 to 50 minutes to finish. It has been further updated to reflect current diverse values and norms. However, many sources feel that the MMPI-3 hasn’t been tested thoroughly enough and do not use it consistently. 

MMPI diagnostic criteria 

After questions are answered, the responses are plotted on a graph. The X-axis has two categories of different scales. Originally there were four content scales, but this has been further broken down as the scales have been developed. The two categories include four content scales and 10 clinical scales.

The first four content scales help the clinician determine the validity of the profile. 

• ? represents the number of questions completed incorrectly with either no attempt or both ‘true’ and ‘false’ selected.
• L for ‘Lie’  shows any attempt by the respondent to misrepresent themselves in a more positive light. Some responses in this area are normal, but there is a limit that shows the profile is invalid due to trying to fake good. 
• F or ‘frequency’ shows any random response, exaggeration, or downplaying of symptoms. This can show a variable response inconsistency or a true response inconsistency. 
• K to gauge ‘defensiveness,’ or evasion of stressful content. An individual with a high K score is likely to have scales that are lower than they should be. The MMPI-2 offered a K-corrected option for the scales, but it is not empirically tested. 

The 10 ‘clinical scales’ are for measuring the presence of psychiatric syndromes.

1 or HS	Hypochondriasis which detects an unusually high level of concern over one’s medical health without cause. Psychological hypochondriasis is typically vague and related to the head and stomach.
2 or D	Depression. High scores here indicate clinical depression and overall dissatisfaction with life.
3 or Hy	Hysteria, which is something of a combination scale and can indicate anxiety, dissociative traits, or general paranoia.
4 or Pd	Psychopathic deviate. Can sometimes be misunderstood as it indicates difficulty with family or authority figures, but can also indicate a high level of morality that isn’t dependent upon society’s definition of right and wrong. This scale can go either way and needs to be interpreted with caution.
5 or Mf	Continuum of masculinity-femininity. It is important to note that this is based on stereotypical, traditional masculine and feminine roles. Questions are tied to activities, sensitivity, and aesthetic preferences. Again, caution is recommended with interpretation as this is a very different concept now than it was in the mid-20th century.
6 or Pa	Paranoia. Measures things like grandiosity, suspiciousness, and rigidity. Think of this scale as general distrust of the world.
7 or Pt	Psychasthenia or obsessive-compulsive tendency. It may identify tendencies like unusual fears, difficulty concentrating, and a tendency to be highly self-critical.
8 or Sc	Schizophrenia. Should not be confused with a diagnostic tool as this scale identifies the tendencies, but not diagnostic criteria. Questions may concern impulse control, bizarre thinking, social alienation, and other related issues.
9 or Ma	Hypomania which identifies elevated mood, overly high excitement, labile mood and other tendencies associated with elevated energy levels.
0 or Si	Social introversion which measures the tendency to avoid interacting with groups or to feel awkward and withdrawn. Again, it is important to interpret this one carefully as introversion is an acceptable trait as long as the individual doesn’t feel like it interferes negatively with their lives.

On these 10 scales, the average person would score between 30 and 70. Scores above that level would be considered concerning. Scores are rarely taken individually and are mostly examined from a profile perspective or a combination of scores. For example, a common profile is a combination of a high 4 and 6 and a low 5 and is often referred to as a warning for low empathy and potential “psychopathic” tendencies. 

This complicated interpretation is one of several reasons that the MMPI can only be used by trained individuals with specific licenses. Psychologists and psychological associates, as well as some Licensed Professional Counselors, are eligible, but most life coaches and similar licenses would not be eligible unless under the supervision of a psychologist for interpretation.

MMPI downsides

As with many psychological assessments, the best chances of success occur when the individual being assessed is willing to participate and is open and honest. Despite the fact that the MMPI can differentiate a fake profile from an honest one, a fake test still leaves an invalid profile that doesn’t provide as much, if any useful information and is a waste of the clinician and client’s time.

The lengthiness of the MMPI is often cited as a difficulty in using the test. It can take an hour (or longer) for the individual to fill out and they may struggle to focus, lose track, or get bored while taking it, causing mistakes, invalid profiles, or incomplete tests.  

Additionally, while computer scoring programs are available, none are as in-depth as human scoring and evaluation, which means robust information gathering is time-consuming for the patient and the clinician. The shorter versions can be helpful but lack the reliability and validity of the longer versions. 

Furthermore, while difficulty accessing the test is a positive for dealing with individuals who may try to fake a personality assessment, it is a potential con for some clinicians as it requires a specific license and training to order the test and can be costly to an individual clinician who may be in private practice or just getting started. This cost ranges from $1,500 to $3,500 and tends to be passed on to the client or their insurance as a full psychological evaluation, which typically includes the MMPI (which takes several sessions to complete) as a standard. 

Pros of using the MMPI

The MMPI has many benefits over other assessments used in personality assessment. While other assessments measure personality and disorders, none measure as efficiently and completely as the MMPI. The MMPI measures across the personality and pathology spectrum. If a clinician is only able to administer one test for a client, the MMPI would be their best bet for a comprehensive test.

The MMPI is also not based on any specific personality theory. Rather, it is constructed using more symptoms and real-world experiences. Because of this, it can be utilized by any clinician with any theoretical orientation as long as they have the appropriate training and credentials. 

The MMPI-2 also provides information about the individual’s test-taking attitude, which can show the therapist that the client is careless, defensive, or exaggerating their problems. This can indicate the individuals are trying to fake good or bad, or that they aren’t taking the assessment seriously. This attitude often extends to therapy as well, so the clinician can be prepared to address or manage this perspective.