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(p. 116) Assessing MMPI-2 Profile Validity 

(p. 116) Assessing MMPI-2 Profile Validity
(p. 116) Assessing MMPI-2 Profile Validity

James N. Butcher

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Subscriber: null; date: 21 September 2017

The most important step in the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) profile interpretation involves the initial determination of whether the profile contains valid, useful, and relevant information about the client’s personality and clinical problems. A number of indices available on the MMPI-2 aid the clinician in determining whether the client’s item responses provide key personality information or simply reflect response sets or deceptive motivational patterns to fend off the assessor as to the client’s true feelings and motivations. This brief introduction to assessing MMPI-2 profile validity will provide the following: a summary of each of the useful response indices contained on the MMPI-2, a strategy for evaluating the validity indices, and key references for the information presented.

Response Indices

Cannot Say Score

This index simply reflects the number of omitted items in the record and is used as an index of cooperativeness. If the item omissions occur at the end of the booklet (beyond item 370), the validity and clinical scales may be interpreted, but the supplemental and MMPI-2 content scales should not be interpreted. The content of omitted items often provides interesting information about the client’s problems. If the individual has omitted more than 10 items, the MMPI-2 scales should be evaluated to determine the percentage of omitted items that appear on a particular scale. For example, a large number of items could appear on a particular scale, thereby reducing its value as a personality measure. If the person has omitted more than 30 items, the response record is probably insufficient for interpretation, particularly if the omissions fall within the first 370 items.

The L Scale

The L scale measures cooperativeness and willingness to endorse faults or problems. Individuals who score high on this scale (T > 60) have presented an overly favorable picture of themselves. If the L score is greater than 65, the individual has claimed virtue not found among people in general. The L scale proves particularly valuable in situations such as personnel screening or forensic cases because many individuals assessed in these settings try to put their best foot forward and present themselves as “better” adjusted than they really are.

The K Scale

The K scale was developed as a measure of test defensiveness and as a correction for the tendency to deny problems. The profiles of persons who respond defensively on the MMPI-2 are adjusted (p. 117) to offset their reluctance to endorse problems by correcting for the defensiveness. Five MMPI scales include corrections by adding a determined amount of the K score to the scale scores of Hs, Pd, Pt, Sc, and Ma. The K scale appeared to operate for MMPI-2 normative subjects much as it did for the original MMPI subjects. Consequently, the K weights originally derived for the MMPI stayed the same in the MMPI-2. In the MMPI-2, both K corrected and non-K corrected profiles can be obtained for psychologists interested in using non-K corrected scores.

The S Scale or Superlative Self-Description Scale

The S scale is an empirical measure developed by contrasting individuals who took the MMPI-2 in an employment selection situation from the normative sample. Applicants usually prove defensive when assessed in an employment screening context. Even well-educated individuals who apply for a highly desirable job tend to approach the MMPI-2 items with a cognitive mindset to convince the psychologist that they have a sound mind, high responsibility, strong moral values, and great capacity to work effectively with others. In their efforts to perform well on personality evaluation, applicants tend to deny psychological symptoms, aggressively disclaim moral flaws, and assert themselves as responsible people who get along extremely well with others and have the ability to compromise in interpersonal situations for the good of safety. In addition, they report being responsible and optimistic about the future, and they assert that they have a degree of good adjustment that most normals do not. In sum, they present themselves in a superlative manner, claiming superiority to the average person in terms of their mental health and morality. The five subscales contained on the S scale are described as follows: Beliefs in Human Goodness, Serenity, Contentment with Life, Patience/Denial of Irritability and Anger, and Denial of Moral Flaws.

The F Scale

The F scale is an infrequency scale that is sensitive to extreme or exaggerated problem endorsement. The items on this scale include very rare or bizarre symptoms. Individuals who endorse a lot of these items tend to exaggerate symptoms on the MMPI-2. High F responding frequently occurs in individuals with a mindset to convince professionals that they need to have psychological services. This motivational pattern also occurs among individuals with a need to claim problems in order to influence the court in some forensic cases, where the appearance of mental illness might benefit a defendant. High-ranging F scores can raise several possible interpretations: The profile could be invalid because the client became confused or disoriented or got mixed up in responding. The F scale is also elevated in random response records. High F scores also occur among clients who malinger or producing exaggerated responding in order to falsely claim mental illness, as in mental disability claim cases.

The F(B) Scale

The F(B) scale, or Back F scale, was developed for the revised version of the MMPI to detect possible deviant responding to items located toward the end of the item pool. Some subjects may modify their approach to the items partway through the item pool and answer in a random or unselective manner. Since the items on the F scale occur earlier in the test, before item number 370, the F scale will not detect deviant response patterns occurring later in the booklet. The 40-item F(B) scale was developed following the same method as for the original F scale, that is, by including items that had low endorsement percentages in the normal population. Suggested interpretations of the F(B) scale include the following considerations: If the F scale is above T = 90, no additional interpretation of F(B) is indicated, since the clinical and validity scales remain invalid by F scale criteria; if the T score of the F scale is valid (i.e., below a T = 89), and the F(B) is below T = 70, then a valid response approach is indicated throughout the booklet and no additional interpretation is needed; or if the T score of the F scale is valid (i.e., below a T = 89), and the F(B) is above a T = 90 (i.e., if the original F scale is valid and the individual has (p. 118) dissimulated on the later part of the booklet), then an interpretation of F(B) is needed. In this case, interpretation of the clinical and validity scales is possible; however, interpretation of scales such as the content scales, which require valid response to the later appearing items, should be deferred.

The F(P) Scale

The Psychopathology Infrequency Scale F(P) was developed to assess infrequent responding in psychiatric settings. This scale proves valuable in appraising the tendency for some people to exaggerate mental health symptoms in the context of patients with genuine psychological disorder. A high score on F(P), for example, above a T score of 80, indicates that the individual has endorsed more bizarre item content than even inpatient psychiatric cases endorse.


Two inconsistency scales for determining profile validity have been included in the MMPI-2. These scales are based on the analysis of the individual’s response to the items in a consistent or inconsistent manner. The first scale, True Response Inconsistency (TRIN), is made up of 20 pairs of items in which a combination of two true or two false responses qualifies as semantically inconsistent—for example, a pair of items that contain content that cannot logically be answered in the same direction if the subject has responded consistently to the content.

TRIN can aid in the interpretation of scores on L and K, since the former is made up entirely of items that are keyed false and the latter is made up of items all but one of which is keyed false. Thus, an individual who inconsistently responds “false” to MMPI-2 pairs of items that contain opposite content will have elevated scores on scales L and K that do not reflect intentional misrepresentation or defensiveness. An individual whose TRIN score indicates inconsistent “true” responding will have deflated scores on L and K that do not reflect a particularly honest response pattern or lack of ego resources.

The Variable Response Inconsistency (VRIN) scale may help interpret a high score on F. VRIN is made up of 49 pairs (true-false; false-true; true-true; false-false) of patterns. The scale is scored by summing the number of inconsistent responses. A high F in conjunction with a low to moderate VRIN score rules out the possibility that the F score reflects random responding.

A Controversial Malingering Scale to Avoid

MMPI-2 users should remain aware of a problem validity scale that was developed for use in personal injury litigation to detect “malingering” of claims but has been more broadly expanded for use in all settings in which the MMPI-2 is used. The test publisher recently changed the name of the Fake Bad Scale to Symptom Validity Scale to avoid the disparaging term “fake bad” as a result of recent controversy over its use. The scale is the Lees-Haley Fake Bad Scale (FBS) published in 1991 by Lees-Haley, Fox, and Glenn. One major problem with the scale is that it contains a substantial number of items that assess actual physical problems or stress-related symptoms. Thus, the scale has a high proportion of false negatives (i.e., It classifies a high number of people who have actual physical or mental health problems as “malingering.”). As a result of this high classification error rate, a number of court cases have seen use of the scale excluded as evidence because of the likelihood of misclassifying patients with genuine problems as “malingering” (see references dealing with the FBS controversy).

Validity Assessment Guidelines

The following guidelines or strategies are recommended for determining the interpretability of profiles:

  • Clues to non-content-oriented responding

    • High Cannot Say’s (≥ 10)

      • Noncompliance

    • Preponderance of T or F

      • Careless or devious omissions

    • VRIN greater than 80

    • TRIN greater than 80

      • “Yea-saying” or “Nay-saying” (depending on whether the score is TRIN [T] or TRIN [F])

  • Indicants of defensive self-presentation

    1. 1. Overly positive self-presentation, leading to a somewhat attenuated record, if any, of these conditions, is present

      • Cannot Say between 5 and 29

      • L over 60 but less than 65

      • K over 60 but less than 69

      • S over 65

    2. 2. Likely invalid MMPI-2 because of test defensiveness if any of the following conditions are present:

      • Cannot Say greater than 30

      • L greater than 66

      • K greater than 70

      • S greater than 70

  • Indicators of exaggerated responding and malingering of symptoms

    1. 1. Excessive symptom claiming

      • F (infrequency) greater than 90

      • F(B) greater than 90

      • F(P) greater than 80

    2. 2. Possibly exaggerated-invalid range

      • F greater than 100

      • F(B) greater than 10

      • F(P) greater than 90

    3. 3. Likely malingering

      • F greater than 109, with VRIN less than or equal to 79

      • F(B) greater than 109, with VRIN less than or equal to 79

      • VRIN less than 79, with VRIN less than or equal to 79

      • F(P) greater than 100, with VRIN less than or equal to 79

References and Readings

Butcher, J. N. (2011). A beginner’s guide to the MMPI-2 (3rd ed.). Washington, DC: American Psychological Association.Find this resource:

    Butcher, J. N., Arbisi, P. A., Atlis, M., & McNulty, J. (2003). The construct validity of the Lees-Haley Fake Bad Scale (FBS): Does this scale measure malingering and feigned emotional distress? Archives of Clinical Neuropsychiatry, 18, 473–485.Find this resource:

    Butcher, J. N., Gass, C. S., Cumella, E., Kally, Z., & Williams, C. L. (2008). Potential for bias in MMPI-2 assessments using the Fake Bad Scale (FBS). Psychological Injury and the Law, 1, 191–209.Find this resource:

    Butcher, J. N., & Han, K. (1995). Development of an MMPI-2 scale to assess the presentation of self in a superlative manner: The S scale. In J. N. Butcher & C. D. Spielberger (Eds.), Advances in personality assessment (Vol. 10, pp. 25–50). Hillsdale, NJ: Erlbaum.Find this resource:

      Gass, C. S., Williams, C. L., Cumella, E., Butcher, J. N., & Kally, Z. (2010). Ambiguous measures of unknown constructs: The MMPI-2 Fake Bad Scale (aka Symptom Validity Scale, FBS, FBS-r). Psychological Injury and the Law, ePub ahead of print. doi: 10.1007/s12207-009-9063-2.Find this resource:

      Lees-Haley, P. R., English, L. T., & Glenn, W. J. (1991). A Fake Bad Scale on the MMPI-2 for personal injury claimants. Psychological Reports, 68, 203–210.Find this resource:

      Wetter, W, Baer, R. A., Berry, D. T, Smith, G. T, & Larsen, L. (1992). Sensitivity of MMPI-2 validity scales to random responding and malingering. Psychological Assessment, 4, 369–374.Find this resource:

      Williams, C. L., Butcher, J. N., Gass, C. S., Cumella, E., & Kally, Z. (2009). Inaccuracies about the MMPI-2 fake bad scale in the reply by Ben-Porath, Greve, Bianchini, and Kaufmann (2009). Psychological Injury and Law, 2, 182–197.Find this resource:

      Related Topics

      Chapter 22, “Interpreting Clinical Scale Scores on the MMPI-2”

      Chapter 23, “Interpreting Supplementary Scales of the MMPI-2”

      Chapter 26, “Interpreting Test Scores and Their Percentile Equivalents”