47,XYY individuals are males who are often tall but otherwise show normal phenotypes. Early studies suggested a possible correlation between 47,XYY and antisocial behavior and subnormal intelligence, but most 47,XYY individuals do not know their karyotype and lead normal lives. Triple X (47,XXX) individuals are females who are often tall but otherwise show normal phenotypes, though some may exhibit abnormal secondary sex characteristics or learning disabilities.