Minnesota Multiphasic Personality Inventory or MMPI is used to assess personality objectively. It is a self-report assessment that is used for individuals 18 and over. The adolescent version is knowns as the MMPI-A and is used for individuals between 14 and 18 years of age. It is the most widely used assessment and helps distinguish clinical illness from normal personality traits.

The MMPI consists of 10 Clinical Scales:

  1. Hypochondriasis (Hs): complaints related to bodily functioning
  2. Depression (D): hopelessness, helplessness, and dissatisfaction with life
  3. Hysteria (Hy): poor physical health, shyness, cynicism, headaches, and neuroticism
  4. Psychopathic Deviate (Pd): social maladjustment, social alienation, and complaints related to authority figures
  5. Masculinity/Femininity (MF): how rigid is the person conforming to gender roles
  6. Paranoia (Pa): interpersonal sensitivity and suspiciousness
  7. Psychasthenia (Pt): obsessive-compulsive symptoms along with self-criticisms and guilt
  8. Schizophrenia (Sc): bizarre thoughts, social isolation, interpersonal issues, and unrealistic beliefs
  9. Hypomania (Ma): milder degree of mania (excitement, unstable mood, and flight of ideas)
  10. Social Introversion (Si): lack of comfort with social interactions, limited social skills, prefer to be alone

All scores have a mean of 50 and a standard deviation of 10. A score above 65 suggests pathology in each of the clinical scales. If two or more scales are above 65, the highest two (or sometimes three) are taken together when interpreting results.

Validity scales are considered when interpreting the results of MMPI:

  • ?: refers to the numbers of questions skipped by the individual, higher score can be due to intellectualizing or paranoia
  • L: Lie scale, high score can be due to perfectionistic self-image and defensiveness
  • F: Infrequency: refers to looking bad, deviant or antisocial
  • K: guardedness and not opening up to internal conflicts
  • VRIN & TRIN: consistent or contradictory response style

MMPI also has Supplementary and Content Scales used to assess other factors such as anxiety, alcoholism, and fears.