The original intent of the MMPI enterprise was to facilitate the treatment of disturbed and distressed individuals. The more fully we understand the person in front of us, the more effectively and quickly we can intervene. Historically the clinical use started, as best I can infer, in pursuit of the refinement of differential diagnosis. The MMPI initially provided a quantification of particular elements of the person’s disorder, and the other inferences and predictions began to accumulate over time. Short of mental health professionals, the MMPI was almost immediately adopted in VA settings after World War II. Psychotherapeutic help was crucial; at that time etiology was mostly loose speculation.


Early on, it became evident that there was a great amount of information that was being communicated by the code types above and beyond what was available in any way from the scales individually. This prompted Hathaway to spend two years in a self-imposed isolation reading charts from which the MMPI results had been removed, and he dictated summaries of almost 1000 cases. Thus, the clinician could look up the patient’s code in the Atlas and see what was going on with others who obtained similar profiles (Hathaway & Meehl, 1951). Numerous other studies have expanded greatly on our body of code-specific information. The works of Marks and Seeman, 1963, Gilberstadt and Duker, 1965, and the books on adolescents by Hathaway and Monachesi, 1961, and of Marks, Seeman, and Haller, 1974, particularly stand out in the elaboration of code type meanings.


The great glaring empty space in the accumulating editions of the DSM has been the persisting absence of any corresponding systematic array of etiologies. The DSM diagnoses are symptom collections that often overlap, and although some categories are naturally well defined, many are seriously ambiguous as to any precise boundaries between them. The categorical diagnosis model also creates what I believe are false and needless struggles over the normal versus diagnostically pathological boundary, which also carries over into the arbitrary "within normal limits" MMPI-2 cutoff. This leads many to a needless rejection of much valuable information; see the discussion of the "normal range" problem in the Counseling and Coaching section of this website.


Thirty years ago, in exploring what makes the scales and code types hold together, I began considering the hypothesis that there may be a central dimension of fear for each of the eight clinical scales (as former seminar students can attest to my mounting preoccupation). Moving from the eight spectra of fear (Caldwell, 2001) to the far greater etiologic specificity of the code types, as of this writing my postulated system has evolved into a set of 23 code type etiologies. This is still very much a "work in progress" with much to be added and refined. I think that the foundation of a comprehensive array of testable and disprovable etiologies would be the final and finest culmination of Hathaway’s gift to us.






Caldwell, A. B. (2001). What do the MMPI scales fundamentally measure? Some hypotheses.
Journal of Personality Assessment, 76, 1-17.


Gilberstadt, H., & Duker, J. (1965). A handbook for clinical and actuarial MMPI interpretation.
Philadelphia: Saunders.


Hathaway, S. R., & Meehl, P. E. (1951). An atlas for the clinical use of the MMPI. Minneapolis:
University of Minnesota Press.


Marks, P. A., & Seeman, W. (1963). The actuarial description of abnormal personality.
Baltimore: Williams & Wilkins.


Marks, P. A., Seeman, W., & Haller, D. L. (1974). The actuarial use of the MMPI with adolescents and adults. Baltimore: Williams & Wilkins.