THE FOUR BASIC HYPOTHESES REGARDING THE POLICE PERSONALITY ARE THE WORKING PERSONALITY, THE ORGANIZATIONAL SELECTION, THE SELF-SELECTION, AND THE NULL HYPOTHESES. ACCORDING TO THE WORKING PERSONALITY HYPOTHESIS, THOSE WHO ENTER POLICE WORK ARE NO DIFFERENT THAN ANYONE ELSE, BUT THE NATURE OF THEIR WORK LEADS THEM TO DEVELOP A CERTAIN WORKING PERSONALITY. THE STRENGTH OR DISTINCTIVENESS OF THIS PERSONALITY IS POSITIVELY RELATED TO THE LENGTH OF TIME SPENT ON THE POLICE FORCE. THE ORGANIZATIONAL SELECTION HYPOTHESIS STATES THAT 'NORMAL' PEOPLE APPLY FOR POLICE POSITIONS, BUT DUE TO RECRUITMENT PROCEDURES, ONLY CERTAIN PERSONALITY TYPES ARE CHOSEN. THE SELF-SELECTION HYPOTHESIS STATES THAT ONLY CERTAIN PERSONALITY TYPES APPLY FOR POLICE WORK. THE FINAL HYPOTHESIS -- THE NULL HYPOTHESIS -- CLAIMS THAT THERE IS NO POLICE PERSONALITY. LITERATURE ON THE POLICE PERSONALITY WAS EVALUATED TO DETERMINE THE VALIDITY OF VARIOUS STUDIES. A TOTAL OF 20 PAPERS RELATED TO THE SUBJECT WERE FOUND. THESE STUDIES USED SEVERAL TESTS, INCLUDING THE KUDER PREFERENCE RECORD, THE ROHRSCHACH INKBLOT TEST, THE MINNESOTA MULTIPHASIC PERSONALITY INVENTORY, AND OTHERS, TO DETERMINE THE PERSONALITY CHARACTERISTICS OF DIFFERENT GROUPS OF POLICE OFFICERS. THE STUDIES AND THEIR FINDINGS ARE BRIEFLY SUMMARIZED AND A DISCUSSION FOLLOWS. THE DISCUSSION REVEALS MAJOR PROBLEMS WITH THE RESEARCH, WHICH INCLUDE LACK OF RELEVANT CONTROL GROUPS, INADEQUATE SAMPLING, LACK OF UNIFORM SUCCESS CRITERIA, QUESTIONABLE VALIDITY, INAPPROPRIATE INTERPRETIVE NORMS, AND INADEQUATE CONTROL OF EXTRANEOUS VARIANCE. SUGGESTIONS FOR RESOLVING THESE DIFFICULTIES ARE PRESENTED FOR FUTURE USE. OF THE 20 STUDIES WHICH WERE ANALYZED, ONLY 10 WERE FOUND TO BE ADEQUATE. THIS STUDY SHOWS THAT CONTRARY TO POPULAR BELIEF, THERE IS LITTLE EMPIRICAL EVIDENCE TO SUPPORT THE NOTION OF A POLICE PERSONALITY. HOWEVER, THESE STUDIES ALSO REVEAL THE FACT THAT CERTAIN PERSONALITY TYPES MAY BE ATTRACTED TO POLICE WORK, SUPPORTING THE SELF-SELECTION HYPOTHESIS. REFERENCES ARE PROVIDED. (BAC)