STUDY SUBJECTS INCLUDED 204 BLACK, 193 WHITE, AND 4 OTHER OFFENDERS WHO ENTERED THE DEPARTMENT FROM SEPTEMBER THROUGH DECEMBER 1975. AS PART OF THE REGULAR ADMISSIONS PROCEDURE, DATA WERE GATHERED ON BIRTH ORDER, FAMILY SIZE, AND NUMBER OF PRIOR CONVICTIONS. THE ONLY STATISTICALLY SIGNIFICANT RELATIONSHIP FOUND IS BETWEEN RECIDIVISM AND THE FIRST-BORN BIRTH-ORDER CATEGORY. FEWER FIRST-BORN OFFENDERS THAN OFFENDERS IN OTHER BIRTH-ORDER CATEGORIES (ONLY-, SECOND-, MIDDLE-, OR LAST-BORN) WERE RECIDIVISTS. THIS FINDING AGREES WITH OTHER STUDIES SHOWING DIFFERENCES IN INTELLIGENCE, ACADEMIC MOTIVATION AND ACHIEVEMENT, AFFILIATION, ATTAINMENT OF MILITARY RANK, AND OTHER AREAS BETWEEN FIRST-BORN AND OTHER BIRTH-ORDER POSITIONS. THE DATA DO NOT INDICATE SIGNIFICANT EFFECTS ON RECIDIVISM FOR FAMILY SIZE, FOR ANY BIRTH-ORDER CATEGORY OTHER THAN FIRST-BORN, OR FOR ANY INTERACTION OF FAMILY SIZE AND BIRTH ORDER. SEVERAL OTHER STUDIES HAVE FOUND DISTINCT EFFECTS FOR THESE VARIABLES. GUIDELINES FOR FURTHER RESEARCH ARE SUGGESTED. SUPPORTING DATA AND A LIST OF REFERENCES ARE INCLUDED. (LKM)