Evaluating the similarity of MMPI-2 and MMPI profiles: reply to Dahlstrom and Humphrey

We review issues that have arisen in exchanges with Dahlstrom and Humphrey (Dahlstrom & Humphrey, 1996; Humphrey & Dahlstrom, 1995) about assessing the comparability of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the MMPI. We point out the limitations of Q correlations (without contending that D(2) is "the only legitimate function of profile comparability," as Dahlstrom and Humphrey, 1996, p. 350, claim we do), and explain why Dahlstrom and Humphrey's (1996) new Q-correlational results, correctly interpreted, are consistent with our own previous observations and conclusions. We stress again the importance of both overall profile elevation and profile "definition" in making code-type assignments. Nonrestrictive code types ignore these profile characteristics, and their use needlessly lowers MMPI-2/MMPI code-type congruences and raises the incidence of profile misinterpretations. Our recommendation of well-defined MMPI-2 code types stands.     

Evaluating the Similarity of MMPI-2 and MMPI Profiles: Reply to Dahlstrom and Humphrey

We review issues that have arisen in exchanges with Dahlstrom and Humphrey (Dahlstrom & Humphrey, 1996; Humphrey & Dahlstrom, 1995) about assessing the comparability of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) and the MMPI. We point out the limitations of Q correlations (without contending that D² is "the only legitimate function of profile comparability," as Dahlstrom and Humphrey, 1996, p. 350, claim we do), and explain why Dahlstrom and Humphrey's (1996) new Q-correlational results, correctly interpreted, are consistent with our own previous observations and conclusions. We stress again the importance of both overall profile elevation and profile "definition" in making code-type assignments. Nonrestrictive code types ignore these profile characteristics, and their use needlessly lowers MMPI-2/MMPI code-type congruences and raises the incidence of profile misinterpretations. Our recommendation of well-defined MMPI-2 code types stands.     

Comparability of MMPI and MMPI-2 profile patterns: Ben-Porath and Tellegen's inappropriate invocation of Mahalanobis's D2 function

Ben-Porath and Tellegen (1995) claimed that the data in the article by Humphrey and Dahlstrom (1995) were improperly analyzed by means of Q correlations between raw scores earned by the individuals in the forensic sample to establish pattern comparability between the original Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) and the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989), which were then contrasted with Q correlations between the corresponding T-score patterns. Ben-Porath and Tellegen (1995) contended that the Q correlation is affected by random factors and that a generalized distance function, D2, is the only legitimate index of profile comparability. Data are presented here to show that the Q correlation serves as a reliable index of pattern comparability, relatively unaffected by differences in profile elevation. The Mahalanobis (1936) D2 index is too heavily weighted with differences in profile elevation serve as the proper index of equivalence in profile patterning. The findings in the Humphrey and Dahlstrom (1995) article were based on appropriate data-analytic procedures because the primary concern is their investigation was the extent to which the patterns of T-score profiles from the original MMPI and the MMPI-2 are comparable when the raw-score patterns are virtually identical.     

Comparability of MMPI and MMPI-2 Profile Patterns: Ben-Porath and Tellegen's Inappropriate Invocation of Mahalanobis's D² Function

Ben-Porath and Tellegen (1995) claimed that the data in the article by Humphrey and Dahlstrom (1995) were improperly analyzed by means of Q correlations between raw scores earned by the individuals in the forensic sample to establish pattern comparability between the original Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) and the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989), which were then contrasted with Q correlations between the corresponding T-score patterns. Ben-Porath and Tellegen (1995) contended that the Q correlation is affected by random factors and that a generalized distance function, D², is the only legitimate index of profile comparability. Data are presented here to show that the Q correlation serves as a reliable index of pattern comparability, relatively unaffected by differences in profile elevation. The Mahalanobis (1936) D² index is too heavily weighted with differences in profile elevation serve as the proper index of equivalence in profile patterning. The findings in the Humphrey and Dahlstrom (1995) article were based on appropriate data-analytic procedures because the primary concern is their investigation was the extent to which the patterns of T-score profiles from the original MMPI and the MMPI-2 are comparable when the raw-score patterns are virtually identical.     

Code-type comparability of the MMPI and MMPI-2: analysis of recent findings and criticisms

The introduction of the MMPI-2 has stimulated studies of its comparability with the MMPI. Graham, Timbrook, Ben-Porath, and Butcher (1991) consider the congruence between MMPI-2 and MMPI code types substantial, but Dahlstrom (1992) has questioned their appraisal, criticizing their use of "well-defined" code types. Our own analysis supports Graham and colleagues' (1991) conclusions and provides reasons for favoring narrow code types (such as well- defined code types) over nonrestrictive ones. We also offer a brief historical review of MMPI code typology as background for our recommendation that future MMPI-2 research not be limited to studies of code-type correlates.     

Code-Type Comparability of the MMPI and MMPI-2: Analysis of Recent Findings and Criticisms

The introduction of the MMPI-2 has stimulated studies of its comparability with the MMPI. Graham, Timbrook, Ben-Porath, and Butcher (1991) consider the congruence between MMPI-2 and MMPI code types substantial, but Dahlstrom (1992) has questioned their appraisal, criticizing their use of "well-defined" code types. Our own analysis supports Graham and colleagues' (1991) conclusions and provides reasons for favoring narrow code types (such as well- defined code types) over nonrestrictive ones. We also offer a brief historical review of MMPI code typology as background for our recommendation that future MMPI-2 research not be limited to studies of code-type correlates.     

Assessing depression with the MMPI and MMPI-2

The usefulness of the MMPI (Hathaway & McKinley, 1951 ) and MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) for diagnosing and assessing symptomatic depression has been the subject of considerable debate for a number of years. In this article, we review the relative contributions of the MMPI and MMPI-2 clinical and content scales in predicting depression. Positive predictive power, negative predictive power, and overall classification rate were computed for Scale 2 (D) of the MMPI and MMPI-2 and the Depression content scale (DEP) of the MMPI-2. Scale 2 (D) of both the MMPI and MMPI-2 appears to be moderately accurate in predicting depression. Although some studies suggest that the content scale DEP provides incremental validity over Scale 2 (D) of the MMPI-2, the results of this review indicate that the content scale DEP of the MMPI-2 does not exceed the diagnostic efficiency of Scale 2 in predicting depression.     

MMPI-2 profiles of women with eating disorders in a Dutch day treatment sample

In this study, we examined the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) profiles of 324 Dutch patients with eating disorders at an eating disorder day treatment program. We studied the MMPI-2 profiles in 5 diagnostic eating disorder groups. All diagnostic subgroups showed high mean elevations of the T scores on the same 6 or 7 scales. Remarkable similarities existed between the mean profile configurations. The MMPI-2 distinguished especially in that patients with restricting anorexia nervosa scored lower on one Validity scale (F), two Clinical scales (1 and 2) and several Supplementary and Content scales of the MMPI-2 compared to the other groups. Only on the validity Scale L did they score higher. The MMPI-2 also distinguished patients with the bulimia nervosa purging type who scored higher on Scale 9 and different on several Content and Supplementary scales. We discuss results with regard to other studies of MMPI (Hathaway & McKinley, 1983) and MMPI-2 profiles of women with anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified in inpatient and outpatient settings.     

Comparison of MMPI-2 and MMPI Clinical Scales and High-Point Scores Among Methadone Maintenance Clients

Methadone client volunteers completed the Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1967) and MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) on consecutive days. MMPI2 T-scores were lower by a mean of 4.7 on the clinical scales; when 5 points were added to MMPI-2 T-scores the mean difference was 2.3. Rank order of subjects on scale T-scores was not significantly different between the two instruments. High-point similarity for clinically elevated profile pairs ranged from 61% to 92%, depending upon definition of similarity.     

Comparability of MMPI-2 scales and profiles over time

This study investigated Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) scale and profile comparablilty for MMPI-2 profiles completed on 2 separate occasions by mental health patients receiving treatment at a Veterans Affairs Medical Center (n = 114). Patients were predominantly men (96.5%), with an average age of 44.08 and an average of 12.39 years of education at the time of initial testing. MMPI-2 tests were completed on 2 separate occasions as a routine part of treatment with a mean interval between test administrations of 688 days. Findings were analyzed for the complete sample and for 3 subsamples with different test-retest intervals. MMPI-2 scale test-retest correlation coefficients for the entire sample ranged from .48 to .69 for the Basic scales, .49 to .80 for the Supplementary scales, and .56 to .78 for the Content scales with scale high-point agreement = 38.60%, high 2-point agreement = 16.67%, and high 3-point agreement = 19.30%. High-point agreement for subsets of participants with well-defined high points, 2-points and 3-points was 41.07%, 27.50%, and 25.93% respectively. Pearson r correlation coefficients for T scores across the Basic scales for pairs of profiles averaged .78, suggesting similarity of profile shape across testing occasions. MMPI-2 profiles were also examined in relation to Skinner and Jackson's 3 modal MMPI profile types.     

Syndromal complexity, paradigm shifts, and the future of validation research: comments on Nichols and Rogers, Sewell, Harrison, and Jordan

In this comment, I address a number of the points raised in the reviews of the MMPI-2 Restructured Clinical (RC; Tellegen et al., 2003) Scales by Nichols (2006/this issue) and Rogers, Sewell, Harrison, and Jordan (2006/this issue), and I advocate for changes in assessment validation research. There is little evidence that the "syndromal complexity" Nichols ascribes to the original MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) Clinical Scales is worth preserving. Although their construction does not constitute the paradigm shift claimed by Rogers et al., the RC Scales are promising, psychometrically defensible measures of core features of the original MMPI-2 Clinical Scales. However, validation of inferences from multiscale inventories such as the MMPI-2 is limited at present by a disconnection between the integrative manner in which MMPI-2 profiles are interpreted and the scale-by-scale nature of most MMPI-2 validation studies. Q-sort procedures show promise for operationalizing integrated MMPI-2 interpretations, with both research and teaching applications.     

Validity rates of the Personality Assessment Inventory and the Minnesota Multiphasic Personality Inventory-2 in a VA Medical Center Setting

In this study, we compared protocol validity rates between the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) and the Personality Assessment Inventory (PAI; Morey, 1991) in a veteran population. Veterans (N=472) were administered both instruments as part of routine psychological evaluations. Profile validity was based on previously published criteria. When applying primary validity indicators, inpatients produced significantly fewer invalid PAI profiles (37%) than MMPI-2 profiles (63%). We found similar results among outpatients for which we considered 47% of MMPI-2 profiles invalid compared to only 21% of PAI profiles. When applying both primary and supplementary validity indicators, both inpatients and outpatients continued to produce fewer invalid PAI profiles than MMPI-2 profiles. We discuss factors that may be related to the differences in validity rates.     

Can sex offenders who minimize on the MMPI conceal psychopathology on the Rorschach?

Rorschach sensitivity to minimization is important in forensic evaluations of sex offenders because these individuals frequently deny psychological problems. To study Rorschach minimization, we divided alleged sex offenders according to whether they minimized on the MMPI (Hathaway & McKinley, 1943) or MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) and compared their Rorschachs on indexes of distress, faulty judgment, interpersonal dysfunction, and cognitive distortions. We predicted there would be no differences between MMPI minimizers and nonminimizers on these indexes and that sex offenders of both groups would show greater psychopathology than normative adult samples. Results indicate that mini- mizers produce normal MMPI clinical profiles but still show evidence of psychopathology on the Rorschach. As predicted, sex offenders showed more Rorschach psychopathology than normative samples. Sex offenders' protocols that contained sexual content also showed perceptual distortions. These findings indicate that the Rorschach is resilient to attempts at faking good and may therefore provide valuable information in forensic settings where intentional distortion is common.     

Psychometric characteristics of the MMPI-2 Cook-Medley Hostility scale

The Minnesota Multiphasic Personality Inventory (MMPI; Hathaway & McKinley, 1943) Cook-Medley Hostility scale (Ho) has been studied a great deal because of its relation to coronary disease and mortality. However, little research has been conducted with the Ho scale on the revised MMPI (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989). This study examined the psychometric characteristics of the MMPI-2 Ho scale. Only nine of the original 50 Ho items were slightly changed in the revision. Ho scores were highly correlated with MMPI-2 scales CYN, K, TPA, and ASP, supporting the interpretation of Ho as a measure of cynicism. High correlations with other MMPI-2 scales also suggested that Ho is related to general psychopathology and negative affectivity. Male Ho scorers were rated by their spouses as hotheaded, bossy, demanding, and argumentative. For women, Ho scale scores were less strongly associated with ratings of overt hostility. Principal components analysis of Ho revealed four underlying dimensions: Cynicism, Hypersensitivity, Aggressive Responding, and Social Avoidance.     

Effect of altered instructions on the MMPI-2 profiles of college students who are not motivated to distort their responses

Research has shown that when the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) is administered with instructions designed to make people aware of the validity indexes and when people are encouraged to respond honestly rather than invalidate the test through defensiveness, their scores on validity scales suggest a more candid responding. Before such modified administration procedures can be broadly used to increase the validity of the MMPI (Hathaway & McKinley, 1943) profiles, it is necessary to have more information about the effect of the altered instructions on test performance of people in general. This study involved administering the MMPI-2 to a group of 218 "normals" (college students) with instructions that differed from traditional instructions. Specifically, the test instructions were altered to explain more about the test and the presence of validity scales to apprise participants that disingenuous responding can be detected. The responses of college students taking the test under altered instructions were compared with those of a similar sample of 150 college students who took the test under standard instructions. Although under altered conditions there was a statistically significant tendency for measures assessing defensiveness (L, K, and S) to be lower for some participants (women but not men), the differences were trivial. Modified instructions made little practical difference in test performance when people who were not motivated to deceive on the test were informed of the presence of validity checks on the test.     

Effect of Altered Instructions on the MMPI-2 Profiles of College Students Who Are Not Motivated to Distort Their Responses

Research has shown that when the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) is administered with instructions designed to make people aware of the validity indexes and when people are encouraged to respond honestly rather than invalidate the test through defensiveness, their scores on validity scales suggest a more candid responding. Before such modified administration procedures can be broadly used to increase the validity of the MMPI (Hathaway & McKinley, 1943) profiles, it is necessary to have more information about the effect of the altered instructions on test performance of people in general. This study involved administering the MMPI-2 to a group of 218 "normals" (college students) with instructions that differed from traditional instructions. Specifically, the test instructions were altered to explain more about the test and the presence of validity scales to apprise participants that disingenuous responding can be detected. The responses of college students taking the test under altered instructions were compared with those of a similar sample of 150 college students who took the test under standard instructions. Although under altered conditions there was a statistically significant tendency for measures assessing defensiveness (L, K, and S) to be lower for some participants (women but not men), the differences were trivial. Modified instructions made little practical difference in test performance when people who were not motivated to deceive on the test were informed of the presence of validity checks on the test.     

MMPI-2 in the inpatient assessment of women with eating disorders

The MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) reveals similar patterns across all Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) eating-disorder diagnoses. In this study, 550 women with eating disorders completed the MMPI-2. The 3 highest mean elevations for all eating-disorder diagnostic groups occurred on the same scales in the same order: 2, 7, and 3. The modal code for all groups was 2-7/7-2. However, multivariate analyses using the 16 validity and clinical scales, as well as the 27 content and supplementary scales, indicated that the MMPI-2 also distinguishes among eating disorders, especially in that patients with restricting anorexia report less psychopathology than other groups. These results are compared with the results of past eating-disorder research that used the older MMPI (Hathaway & McKinley, 1983).     

Whither goest our redoubtable mentor, the MMPI/MMPI-2?

Four areas of MMPI use and development toward the year 2000 and beyond are discussed. First, although the MMPI-2 booklet is a clear improvement, we will continue to need to use both profiles, the MMPI-2 for normative purposes and the MMPI profile for pattern interpretation. Applying MMPI expectations to MMPI-2 profiles is a violation of Meehl's basic actuarial prediction concepts. Secondly, as psychologists begin prescribing medications, we may be able to substantially refine drug choices. Thirdly, the measurement of socioeconomic status levels appears to be the major, missing moderator variable in MMPI/MMPI-2 interpretation. Lastly, an effective and positive MMPI/MMPI-2 feedback paradigm is discussed that fits well within the managed care context.