This study was made to determine the comparative stability of response to the items of the Bernreuter Personality Inventory. It was given to inmates of the New Jersey Reformatory for men. By similarity of response by 75% or more of the subjects the items were classified into three groups. The group of positive items consisted of 11 questions which on second administration gave an index of change of 21% and an average change per subject of 2.3. The negative items consisted of 18 questions; the index of change was 21.2% and the average change per subject was 3.9. The neutral items consisted of 96 questions, with a total index of change of 32.5% and an average change per subject of 31.2. Until the influence of situation and the various factors in motivating responses can be definitely stated, the personality questionnaire will remain a dubious clinical instrument. (PsycINFO Database Record (c) 2006 APA, all rights reserved)