THE SUBJECTS WERE ALL MALE VOLUNTEERS CONSISTING OF INMATES OF THE BRITISH COLUMBIA PENITENTIARY IN CANADA AND STUDENTS FROM A LOCAL ADULT EDUCATION CENTER. THE SUBJECTS SAT IN FRONT OF A MEMORY DRUM AND, AFTER A SKIN RESISTANCE MEASURING DEVICE AND SHOCK ELECTRODES WERE ATTACHED, WERE ASKED TO WATCH THE DRUM AS THE NUMBERS 1 THROUGH 12 APPEARED, ROTATING IN SEQUENTIAL ORDER. DURING THE FIRST TRIALS NO SHOCKS WERE ADMINISTERED, BUT IN LATER TRIALS, SHOCKS WERE PASSED THROUGH THE ELECTRODES WHENEVER THE NUMBER 8 APPEARED ON THE DRUM. LOG CONDUCTANCE INCREASES IN THE INTERVAL PRIOR TO THE SHOCK WERE SIGNIFICANTLY SMALLER AND BEGAN LATER FOR THE PSYCHOPATHS THAN FOR THE NONPSYCHOPATHS. THE PSYCHOPATHS WERE LESS RESPONSIVE TO SHOCK THAN WERE THE NONPSYCHOPATHS, ALTHOUGH THEY DID NOT DIFFER SIGNIFICANTLY FROM THE NONCRIMINAL CONTROLS. THERE WERE NO SIGNIFICANT DIFFERENCES AMONG GROUPS IN THE RATE OF RECOVERY FROM THE EFFECTS OF THE SHOCKS. THESE RESULTS ARE CONSISTENT WITH THE HYPOTHESIS THAT THE TEMPORAL GRADIENT OF FEAR AROUSAL AND RESPONSE INHIBITION IS STEEPER FOR PSYCHOPATHS THAN FOR NORMAL PERSONS. GRAPHIC DATA AND REFERENCES ARE INCLUDED. (KBL)