20-124)With the advent of modern psychiatry, homosexuality came to be seen more as an illness than a sin. Opinions as to the origin and nature of homosexuality were once based solely on the study of maladjusted psychiatric patients. Theories formed from such research suggest that disorders in family relationships, particularly between mother and son, are responsible for homosexual behavior. These theories are not convincing, not only because they are based on the assumption that homosexuals are psychologically abnormal, but also because many heterosexuals also come from families in which there are relationship disorders. (Thompson 12, 228) In 1973 homosexuality was removed from the American Psychiatric Association’s official list of mental disorders. Although none of the mental health professions now officially considers homosexuality an illness, there are still prominent theorists who insist that it is. (Ruse 48)More recent theories to account for homosexuality have included those based on biological and sociological factors. Chromosomal studies attempting to isolate genetic Perez 3orientation at birth have been mostly inconclusive. Some social theories have suggested that homosexual behavior may be an adaptive response to situations. For example, a prison inmate might participate in homosexual activities while in prison but return to heterosexuality upon release. Such approaches suggest the sometimes-transient nature of homosexuality and point up the difficulty in identifying homosexuality as an exclusive, clear-cut phenomenon. While such theories can offer explanation about why homosexuality offers in some situations, to date there are no conclusive general theories that can explain the cause of homosexuality. (Ruse 67) Because homosexuality is so controversial and the heavy social pressure against it, many individuals are reluctant to reveal that they are gay. Estimates of the incidence of homosexuality have not o...