THE SAMPLE CONTAINED TWO GROUPS OF YOUNG BOYS BETWEEN THE AGES OF 10 AND 19 WHO HAD BEEN ADMITTED TO THE INPATIENT SERVICE OF THE UNIVERSITY OF MINNESOTA DIVISION OF CHILD PSYCHIATRY DURING A 4-YEAR PERIOD AND WERE RESIDENTS OF A DETENTION CENTER. BOTH GROUPS WERE TALLER THAN AVERAGE AND HAVE EVIDENCED ANTISOCIAL AND AGGRESSIVE BEHAVIOR. ANTHROPOMETRICAL MEASUREMENTS, DERMATOGRYPHICS, AND FAMILY HISTORIES WERE OBTAINED FROM THE SUBJECTS, AND LYMPHOBLASTS FROM THEIR PERIPHERAL BLOOD WERE CULTURED THREE DAYS IN ORDER TO IDENTIFY CHROMOSOMES USING THE STANDARD DRYING METHOD. IN EACH CASE, AT LEAST 10 METAPHASES WERE COUNTED AND 2 CELLS WERE KARYOTYPED. NONE OF THE 46 CASES ANALYZED SHOWED ANY ABNORMALITY EITHER OF THE AUTOSOMAL OR OF SEX CHROMOSOMES. NO CONCLUSIONS WERE POSSIBLE DUE TO THE SMALL SAMPLE SIZE. STUDY DATA AND REFERENCES ARE INCLUDED. (DAG)