CLINICIANS AND BEHAVIORAL SCIENTISTS IN NORTH AMERICA AND PARTS OF EUROPE ARE IN AGREEMENT ON THE DISORDER'S CLINICAL AND BEHAVIORAL FEATURES. THESE INCLUDE EARLY SIGNS OF STEALING, FIGHTING, TRUANCY, RESISTING AUTHORITY; AGGRESSIVE SEXUAL BEHAVIOR; ALCOHOL AND DRUG USE; AND MARKEDLY IMPAIRED CAPACITY TO SUSTAIN LASTING, CLOSE, WARM, AND RESPONSIBLE RELATIONSHIPS WITH FAMILY, FRIENDS, OR SEXUAL PARTNERS. METHODS FOR DIAGNOSIS INCLUDE GLOBAL ASSESSMENTS AND THE DIAGNOSTIC CRITERIA PROPOSED FOR THE NEW DIAGNOSTIC AND STATISTICAL MANUAL (DSM-3) OF THE AMERICAN PSYCHIATRIC ASSOCIATION. BECAUSE DSM-3 DIAGNOSIS OF ANTISOCIAL PERSONALITY DISORDER (APD) CAN BE MADE STRINGENT OR LIBERAL SIMPLY BY MANIPULATING THE NUMBER OF BEHAVIORS REQUIRED TO SATISFY EACH CONDITION, GENERAL USE OF THESE CRITERIA WOULD MAKE APD DIAGNOSIS ALMOST MEANINGLESS WHERE CRIMINALS ARE CONCERNED. FOR EXAMPLE, ONE STUDY SHOWED THAT 59 OF 75 INMATES CLASSIFIED BY THESE CRITERIA WOULD RECEIVE AN APD DIAGNOSIS. A MORE REALISTIC ESTIMATE, BASED ON 15 YEARS OF RESEARCH IN CANADIAN PENAL INSTITUTIONS, IS THAT 25 TO 30 PERCENT OF WHITE PRISON INMATES IN CANADA ARE PSYCHOPATHS IN THE STRICT SENSE. UNPUBLISHED DATA INDICATE QUITE CLEARLY THAT THE SUBSEQUENT CRIMINAL HISTORY OF CAREFULLY DEFINED GROUPS OF PSYCHOPATHIC CRIMINALS IS CONSIDERABLY WORSE THAT THAT OF NONPSYCHOPATHIC CRIMINALS. UNLIKE NONPSYCHOPATHIC CRIMINALS, PSYCHOPATHS WHO WERE FIRST CONVICTED IN ADULT COURT AT AN EARLY AGE WERE SUBSEQUENTLY MORE LIKELY TO ESCAPE AND TO BE CONVICTED OF VIOLENT CRIMES THAN WERE OLDER PSYCHOPATHS. STUDIES OF TWO BIOLOGICAL CORRELATES OF PSYCHOPATHY (ELECTROCORTICAL ACTIVITY AND AUTONOMIC ACTIVITY) INDICATE THAT THE RELATIONSHIP BETWEEN BIOLOGICAL VARIABLES AND CRIMINAL HISTORY DATA DIFFER FOR PSYCHOPATHS AND NONPSYCHOPATHS. ALTHOUGH THESE ANALYSES ARE PRELIMINARY, THEY SUGGEST THAT PREDICTIONS OF CRIMINAL BEHAVIOR VARIABLES ARE BETTER WHEN BIOLOGICAL DATA AND ASSESSMENTS OF PSYCHOPATHY ARE USED IN COMBINATION THAN WHEN EITHER IS USED ALONE. TABLES AND A REFERENCE LIST ARE INCLUDED. (CFW)