Personality deviancy and prison incarceration

Abstract
Personality differences among prison inmates that could be attributed to the number of felony offenses and the length of incarceration were studied. MMPI [Minnesota Multiphasic Personality Inventory] profiles of of 93 inmates of a medium security prison were obtained and analyzed. Special attention was directed to the 5 MMPI variables K [Defensiveness], D [Depression], Pd [Psychopathic deviate], Sc [Schizophrenia] and Ma [Mania]. These 5 variables taken collectively successfully differentiated 1st offenders from repeaters and short-term from long-term inmates. Increased incarceration probably had a harmful effect upon personality.