SINCE THE FIRST OBSERVATION OF A 47,XYY HUMAN IN THE EARLY 1960'S, EXAMPLES OF 47,XYY MALES HAVE BEEN REPORTED FROM AS MANY AS 19 COUNTRIES, INCLUDING THE U.S., ENGLAND, AUSTRALIA, FRANCE, ITALY, HUNGARY, JAMAICA, JAPAN, AND SOUTH AFRICA. HOWEVER, BASED ON THIS MASS OF DATA, NO CLEAR RELATIONSHIP CAN BE ESTABLISHED WITH REGARD TO EXTERNAL GENITALIA, BONE AND JOINT ABNORMALITIES, DENTAL IRREGULARITIES, SKIN DISORDERS, AND SOME HORMONE LEVELS. INCREASED STATURE, DERMATOGLYPHIC ALTERATIONS, POSSIBLE NEUROLOGICAL INVOLVEMENT, ALTERATIONS IN TESTICULAR CELLS, AND SOME SLIGHT CARDIAC ANOMALY MAY, WITH PROPERLY COLLECTED DATA, PROVE TO BE PREDICTABLE FROM THE XYY GENOME. ALTHOUGH AVAILABLE DATA RELEVANT TO PSYCHOLOGICAL AND SOCIAL FUNCTIONING INCLUDE DIAGNOSES, PERSONALITY AND BEHAVIORAL DESCRIPTIONS, CRIMINAL RECORDS, AGE AT FIRST CONVICTION, AND PSYCHOMETRIC SCORES ON TEST OF PERSONALITY AND INTELLIGENCE, NO CONSISTENT PERSONALITY OR BEHAVIORAL CONSTELLATION HAS BEEN SUCCESSFULLY PREDICTED FROM THE XYY COMPLEMENT. TABULAR AND GRAPHIC DATA ARE PROVIDED, ALONG WITH REFERENCES. (AUTHOR ABSTRACT MODIFIED--KBL)