DIFFERENT TERMS--PSYCHOPATHY, SOCIOPATHY, ANTISOCIAL PERSONALITY, ETC.--ALL REFER TO A COMMON CORE OF ATTRIBUTES. TYPICALLY THE PSYCHOPATH ENGAGES IN PERSISTENT ANTISOCIAL BEHAVIOR FROM AN EARLY AGE. IN ADULTHOOD THERE IS A MARKEDLY IMPAIRED CAPACITY TO SUSTAIN INTERPERSONAL RELATIONS AND GOOD JOB PERFORMANCE. LYING, STEALING, FIGHTING, TRUANCY, AGGRESSIVE SEXUAL BEHAVIOR, EXCESSIVE DRINKING, AND DRUG ABUSE ARE COMMON, ALTHOUGH SOME OF THE MORE FLAGRANT BEHAVIORS TEND TO DIMINISH AFTER AGE 30. AGREEMENT ON THE CONCEPT DOES NOT MEAN THAT ALL CLINICIANS AND RESEARCHERS USE THE SAME PROCEDURES TO DIAGNOSE PATIENTS AND TO SELECT RESEARCH SUBJECTS. AMONG THESE PROCEDURES ARE GLOBAL ASSESSMENTS BASED ON INTERVIEWS AND CASE HISTORIES, RESEARCH DIAGNOSTIC CRITERIA (GENERALLY QUITE EXPLICIT AND MORE OBJECTIVE THAN GLOBAL ASSESSMENTS), BEHAVIOR-RATING SCALES, AND SELF-REPORT INVENTORIES. FEW FIRM CONCLUSIONS CAN BE DRAWN FROM ELECTROCORTICAL STUDIES ON PSYCHOPATHS (STUDIES OF ELECTRICAL ACTIVITY IN THE BRAIN CORTEX, INCLUDING ELECTROENCEPHALOGRAMS), PRIMARILY BECAUSE LITTLE WELL CONTROLLED RESEARCH HAS BEEN CONDUCTED IN THIS AREA. AUTONOMIC RESEARCH HAS EXPLORED ELECTRODERMAL (SKIN CONDUCTANCE) AND CARDIOVASCULAR (HEARTBEAT) RESPONSES TO STIMULI. THE MOST CONSISTENT FINDING IS THAT PSYCHOPATHS, IN ANTICIPATION OF AVERSIVE STIMULI, SHOW RELATIVELY SMALL INCREASES IN ELECTRODERMAL ACTIVITY BUT RELATIVELY STRONG CARDIOVASCULAR RESPONSE. ONE VIEW IS THAT THESE RESPONSES CONSTITUTE AN ACTIVE, EFFICIENT COPING PROCESS THAT INHIBITS FEAR AROUSAL. IT MAY BE THAT AN ENHANCED ABILITY TO DISSIPATE AVERSIVE INPUT AND TO INHIBIT ANTICIPATORY FEAR EXPLAINS WHY PSYCHOPATHS EXHIBIT NO CONCERN FOR SITUATIONS THAT HAVE GREAT EMOTIONAL IMPACT FOR MOST PEOPLE. TO SOME EXTENT, THIS INTERPRETATION COULD ACCOUNT FOR THE PSYCHOPATH'S INABILITY TO AVOID PUNISHMENT. IT MAY BE THAT THE CUES THAT HELP MOST PEOPLE AVOID PUNISHMENT ARE TUNED OUT BY THE PSYCHOPATH, IN WHOM THE MEDIATING EFFECTS OF ANTICIPATORY FEAR ARE REDUCED. A LIST OF REFERENCES IS INCLUDED. (LKM)