AMONG THE POLICE CHARACTERISTICS CONSIDERED IN THE RESEARCH REVIEW ARE PSYCHOPATHOLOGY, INTELLIGENCE, ISOLATION AND SECRECY, DEFENSIVENESS, CYNICISM, VIOLENCE, AUTHORITARIANISM, CONSERVATISM, MISPERCEPTION OF PUBLIC OPINIONS, AND ANTI-MINORITY PREJUDICE. RESEARCH ON THE MOTIVATION TO BECOME A POLICEMAN IS ALSO EXAMINED. THE AUTHOR NOTES THAT THE DATA SUBSTANTIATE, WITH SOME QUALIFICATIONS, THE EXISTENCE OF A NONPATHOLOGICAL 'MODAL POLICE PERSONALITY.' HE NOTES THAT METHOLODOGICAL WEAKNESS OF THESE STUDIES PREVENTS AN ASSESSMENT OF THE RELATIVE DEVELOPMENTAL CONTRIBUTIONS OF PREDISPOSING SELF-SELECTION EFFECTS, SOCIOECONOMIC CLASS DETERMINANTS, ORGANIZATIONAL SELECTION AND SELECTIVE ATTRITION, OCCUPATIONAL SOCIALIZATION, AND ROLE-SPECIFIC BEHAVIORS. (AUTHOR ABSTRACT MODIFIED)