THE INITIAL DATA FOR THE MARION COUNTY YOUTH STUDY WAS COLLECTED IN 1964, AND IN 1967 SUBJECTS FROM THE POPULATION OF 1,227 MALES WERE RANDOMLY SELECTED FOR FOLLOWUP INTERVIEWS. USING 2 SAMPLES, 528 OBJECTIVELY DEPENDABLE INTERVIEWS WERE OBTAINED. DELINQUENTS WERE DEFINED AS YOUTHS WHO HAD BECOME OFFICIALLY INVOLVED WITH THE JUVENILE COURT, AND REBELLION WAS IDENTIFIED BY AN ATTITUDINAL BEHAVIOR INDEX. CONTROL VARIABLES INCLUDED SOCIO-ECONOMIC STATUS BASED ON FATHER'S OCCUPATION AND SCHOOL STATUS MEASURED BY ACADEMIC ACHIEVEMENT. ANALYSIS OF THESE VARIABLES INDICATED SIGNIFICANT DIFFERENCES BETWEEN REBELLIOUS AND DELINQUENT BOYS IN SCHOOL SOCIAL LIFE, DRINKING, SMOKING, AND RELATIONS WITH AUTHORITIES. SOCIO-ECONOMIC STATUS WAS NOT A SIGNIFICANT INTERVENING VARIABLE, ALTHOUGH BLUE COLLAR YOUTH APPEARED MORE VULNERABLE TO SCHOOL FAILURE AND THUS WERE MORE LIKELY TO RESPOND WITH DEVIANT BEHAVIOR. SCHOOL FAILURE WAS HIGHEST AMONG THE MOST REBELLIOUS YOUTHS, WHILE NON-REBELLIOUS DELINQUENTS ENJOYED PASSING SUCCESS IN SCHOOL. IN VIEW OF SCHOOL BUREAUCRATIZATION, SOCIAL THEORISTS COULD BENEFIT FROM VIEWING DELINQUENT BEHAVIOR AS PROBING, SEEKING, TESTING ADOLESCENT RESENTMENT. TABLES PROVIDE THE STATISTICAL ANALYSIS. THE APPENDIXES CONTAIN THE QUESTIONNAIRES AND INTERVIEW SCHEDULES USED IN THE MARION COUNTY STUDY AND A REPORT ON THE INFLUENCE OF DEMOGRAPHIC VARIABLES ON JUVENILE BEHAVIOR. APPROXIMATELY 100 REFERENCES ARE PROVIDED.