The MMPI K Scale - Cross-Examining Psych Doctors, Tip #119

     The Minnesota Multiphasic Personality Inventory (MMPI) is a psychological test that is considered the gold standard of test batteries used in medical legal evaluations.  The MMPI-2 was published in 1989 and has many proponents who depend on the test’s validity scales to provide information about the individual’s test-taking attitudes and credibility.  In fact, the MMPI-2 is the most commonly used version of the MMPI by psychologists and psychiatrists.  Every validity and clinical scale performance is described with a T-Score on the MMPI-2 which all have a mean of 50 and a standard deviation of 10.  Further, it is well known and universally accepted that T-Scores of 65 or larger are clinically significant or interpretable.  In this regard, the K Scale is one of the validity scales of the MMPI-2.  T-Scores 65 or higher on the K Scale are associated with the exaggeration of physical disability and distorting the individual’s true psychological condition.