Richard Green's book is the product of a 15-year prospective study of young boys whose gender-role behavior had been characterized as "feminine." It is an outgrowth of previous studies of transsexualism by Green and others which have demonstrated that adult transsexuals consistently exhibited cross-gender behaviors as children. A significant number of homosexual men also have been found to have histories of cross-gender behavior during childhood. These findings generated the major goals of this prospective study: to investigate persistent cross-gender behavior occurring in boys and to study its influence on their emerging sexuality.