PHYSIOLOGICAL ACTIVITY WAS MONITORED WHILE 64 PRISON INMATES AWAITED DELIVERY OF A 120DB TONE DURING A 12-SECOND 'COUNT-DOWN' PROCEDURE. THE INMATES WERE DIVIDED INTO 4 GROUPS ON THE BASIS OF GLOBAL RATINGS OF PSYCHOPATHY AND SCORES ON THE SOCIALIZATION SCALE. TWELVE INMATES IN THE GROUP CONSIDERED TO BE MOST PSYCHOPATHIC (THOSE HAVING HIGH RATINGS OF PSYCHOPATHY AND LOW SOCIALIZATION SCORES) SHOWED LARGER INCREASES IN HEART RATE AND SMALLER INCREASES IN ELECTRODERMAL ACTIVITY IN ANTICIPATION OF THE TONE THAN DID 20 INMATES IN THE GROUP CONSIDERED TO BE LEAST PSYCHOPATHIC (THOSE WITH LOW RATINGS OF PSYCHOPATHY AND HIGH SOCIALIZATION SCORES). THERE WERE NO SIGNIFICANT DIFFERENCES BETWEEN GROUPS IN TONIC AUTONOMIC ACTIVITY THROUGHOUT THE EXPERIMENT. THE PATTERN OF ANTICIPATORY HEART RATE ACCELERATION AND SMALL ELECTRODERMAL AROUSAL WAS NOT FOUND IN INMATES WHO DID NOT HAVE BOTH HIGH RATINGS OF PSYCHOPATHY AND LOW SOCIALIZATION SCORES, BUT WERE CONSIDERED TO BE PSYCHOPATHIC USING GLOBAL CLINIC RATINGS. THESE FINDINGS WERE CONSISTENT WITH THOSE OF SEVERAL PREVIOUS STUDIES AND WERE INTERPRETED AS A REFLECTION OF AN ASSOCIATION BETWEEN PSYCHOPATHY AND THE OPERATION OF EFFICIENT MECHANISMS FOR COPING WITH THREAT. TABULAR DATA AND REFERENCES ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED---DAG)