THE SUBJECTS WERE 144 MALE AND 144 FEMALE STUDENTS IN THE INTRODUCTORY PSYCHOLOGY COURSE AT PURDUE UNIVERSITY (WEST LAFAYETTE, INDIANA). A TOTAL OF 72 SUBJECTS WERE RANDOMLY ASSIGNED TO CONDITIONS IN EACH OF THE FIRST TWO EXPERIMENTS, WHILE 144 PARTICIPATED IN THE THIRD. THREE SEPARATE INVESTIGATIONS WERE CONDUCTED SIMULTANEOUSLY. THE NATURE OF THE BYSTANDER-CULPRIT RELATIONSHIP AND THE SEX OF SUBJECTS WERE CONSIDERED IN ALL THE STUDIES. THE FIRST TWO EXPERIMENTS WERE THOSE IN WHICH THE ROLES OF EXPERIMENTER AND CONFEDERATE WERE PERFORMED BY TWO MALES AND THREE FEMALES. EXPERIMENT 3 VARIED THE SEX OF BOTH THE EXPERIMENTER AND THE CONFEDERATE. THE SOURCE OF FUNDS FOR THE 'BONUS' WAS OSTENSIBLY A GRANT FROM GENERAL MOTORS (CORPORATE SOURCE) IN THE FIRST INVESTIGATION AND THE EXPERIMENTER'S PERSONAL FUNDS (PERSONAL SOURCE) IN THE LAST TWO STUDIES. THE MAJOR DEPENDENT VARIABLES WERE (1) WHETHER THE SUBJECT SPONTANEOUSLY REPORTED THE CONFEDERATE'S MISREPRESENTATION AND (2) WHETHER THE SUBJECT SIGNED A VOUCHER VERIFYING THE CONFEDERATE'S SCORE. IT WAS FOUND THAT THE PROBABILITY OF BYSTANDERS' REPORTING THE DISHONESTY AND REFUSING TO SIGN A DOCUMENT ATTESTING TO THE CONFEDERATE'S SCORE WAS DIFFERENTIALLY AFFECTED BY SITUATIONAL FACTORS AND SEX OF THE BYSTANDER, WRONGDOER, AND AUTHORITY FIGURE. BYSTANDERS WERE MOST APT TO REPORT THE MISDEED WHEN THEY WERE COMPETING AGAINST RATHER THAN WORKING EITHER INDEPENDENTLY OR COOPERATIVELY WITH THE CULPRIT, AT LEAST WHEN THE BONUS WAS PROVIDED BY A LARGE CORPORATION. IN ADDITION, FEMALES WERE MORE LIKELY THAN MALES TO REPORT THE MISDEED WHEN THE VICTIM WAS ANOTHER PERSON RATHER THAN EITHER A CORPORATION OR THE BYSTANDER HIMSELF, AND BOTH SEXES WERE MORE APT TO REPORT A FEMALE WRONGDOER THAN A MALE ONE. PERSONS WHO INITIALLY REPORTED THE MISDEED WERE LESS LIKELY TO BECOME ACTIVE ACCOMPLICES THAN WERE THOSE WHO FAILED TO REPORT IT. FURTHERMORE, LESS WRITTEN VERIFICATION OF THE FALSEHOOD OCCURRED WHEN (1) NONREPORTERS WERE PERFORMING INDEPENDENTLY RATHER THAN EITHER COMPETING AGAINST OR WORKING COOPERATIVELY WITH THE CULPRIT FOR THE BONUS, AND (2) A MALE WAS IN AN IMMEDIATE POSITION OF AUTHORITY. (RCB)