A 1973 SURVEY DIVIDED THE POPULATION OF A SPECIFIC MALE INSTITUTIONALIZED POPULATION INTO A MENTAL GROUP CONSISTING OF RETARDED, DISTURBED, PSYCHOTIC, ALCOHOLIC, OR EPILEPTIC INDIVIDUALS, A PENAL GROUP, AND A MENTAL-PENAL GROUP (E.G., MENTALLY ILL CRIMINALS). THE STUDY CONCLUDED THAT A DEFINITE ASSOCIATION EXISTS BETWEEN THE XYY KARYOTYPE AND THE MALE'S PRESENCE IN A MENTAL-PENAL SETTING. EXAMINATION OF CHROMOSOMAL SURVEYS CONDUCTED IN PENAL, SPECIAL SECURITY, AND MENTAL HOSPITALS IN NORTH AMERICA AND EUROPE REVEALS THAT AT LEAST 147 XYY INDIVIDUALS WERE DETECTED AMONG THE 13,522 SUBJECTS A SIZEABLE INCREASE OVER THE NUMBER OF XYY MALES FOUND PER AN EQUAL NUMBER OF NORMAL NEW-BORN MALES. HOWEVER, XXY MALES ARE ALSO AT A HIGHER RISK FOR INSTITUTIONALIZATION THAN THE NORMAL MALE POPULATION, TECHNICAL PROCEDURES FOR DETERMINING INDIVIDUAL KARYOTYPES ARE SUSCEPTIBLE TO VARIOUS EXTERNAL FACTORS, AND THE COMPARISON OF KARYOTYPES FOR NEW-BORN MALES TO INSTITUTIONALIZED MALES PRESUMES SIMILARITIES IN CLASS, ETHNIC COMPOSITION, AND OTHER VARIABLES. RESEARCH SHOWS THAT OVER 75 PERCENT OF XYY INSTITUTIONALIZED MALES DERIVE FROM FAMILIES WITH A HISTORY OF CRIMINALITY AND/OR OTHER PSYCHOSOCIAL DISTURBANCE, AND THESE DATA SUGGEST THAT THE CIRCUMSTANCES INTO WHICH XYY'S ARE BORN PLAY A MAJOR ROLE IN THE PERSON'S LATER INSTITUTIONALIZATION. A 1971 SCOTTISH STUDY SHOWS THAT THE INSTITUTIONALIZATION EXPECTANCY AMONG XYY MALES IS TWICE AS HIGH AS THAT AMONG CHROMOSOMALLY NORMAL MALES IN THE COUNTRY; HOWEVER, THE CHANCES OF NONINSTITUTIONALIZATION ARE 99.86 AND 99.73 PERCENT FOR CHROMOSOMALLY NORMAL AND XYY MALES RESPECTIVELY. IN CONCLUSION, IT IS STATED THAT EVIDENCE IS NOT SATISFACTORY TO ESTABLISH A LINK BETWEEN XYY'S AND CRIMINALITY, AND GENETIC COUNSELING OF PARENTS MIGHT HAVE THE EFFECT OF LABELING -- XYY MALES WOULD TEND TOWARDS CRIMINAL BEHAVIOR BECAUSE IT IS EXPECTED OF THEM. REFERENCES AND TABLES ARE PROVIDED. (DAG)