THIS INVESTIGATION WAS DESIGNED TO PROVIDE DATA ABOUT THE CHARACTERISTICS OF SOCIAL-POLITICAL ACTION LEADERS AT ONE UNIVERSITY AND TO COMPARE THOSE CHARACTERISTICS WITH OTHER TYPES OR CATEGORIES OF STUDENT LEADERS. NINE RESEARCH HYPOTHESES IN NULL FORM WERE FORMULATED TO FACILITATE STATISTICAL TREATMENT OF THE DATA. FROM A TOTAL OF 559 ELECTED OFFICERS OF STUDENT ORGANIZATIONS ON THE CAMPUS OF INDIANA UNIVERSITY, FIVE CATEGORIES OF STUDENT LEADERS WERE FORMED SO THAT COMPARISONS COULD BE MADE BETWEEN LEADERS OF GROUPS DIFFERING IN STATED PURPOSES AND GOALS. EACH SUBJECT COMPLETED THE "SIXTEEN PERSONALITY FACTOR QUESTIONNAIRE," THE "COLLEGE AND UNIVERSITY ENVIRONMENT SCALES," AND A PERSONAL DATA FORM. THE NINE NULL HYPOTHESES WERE REJECTED. SIGNIFICANT DIFFERENCES WERE OBSERVED AMONG GROUP LEADERS IN TERMS OF MEASURED PERSONALITY CHARACTERISTICS, PERCEIVED CAMPUS ENVIRONMENTAL CHARACTERISTICS, AND SELECTED DEMOGRAPHIC AND PERSONAL CHARACTERISTICS. THESE RESULTS SUGGESTED THAT A UNIQUE COMBINATION OF PERSONALITY TRAITS PRIMARILY INVOLVING RADICALISM, EXPEDIENCY, AND INDEPENDENCE SERVE TO DIFFERENTIATE LEADERS OF SOCIAL-POLITICAL ACTION GROUPS FROM LEADERS OF REFERENT GROUPS. (GD)