By Timothy F. Murphy

In 1929, neurologist John F.W. Meagher observed that "Indulgent male inverts like pleasant, artistic things, and nearly all of them are fond of music. They also like praise and admiration. They are poor whistlers. Their favorite color is green . . . where most individuals prefer blue or red."1 Like many clinicians and psychologists before him, Meagher believed that some people were homosexual for genetic reasons, and that these account for the alleged similarity in tastes and behavior. Others pointed to genetics as an explanation of homosexuality, too. The psychologist Richard von Kraftt-Ebing (1840-1902) said in 1886 that "An explanation of contrary sexual feeling may be found in the fact that it represents a peculiarity bred in descendants, but arising in ancestry."2

Not everyone has turned to genetics to explain homosexuality, especially since homosexuality could arise situationally. But the idea that genetics was responsible for some homosexuality led some clinicians to express worries that homosexual men and women would pass that sexuality on to their own children, should they have them. Even the foremost advocate of the rights of homosexual people of his time, Magnus Hirschfeld (1868-1935) cautioned that "from the viewpoint of race hygiene, the marriage of a homosexual is a risky undertaking."3

The idea that sexual orientation was biological for some people did not, however, close the door to the idea of therapy for homosexuality. Krafft-Ebing thought a return to heterosexuality was possible for at least some 'inverts.' Yet the idea of a biological basis for sexuality did give some psychologists pause about whether psychotherapies could work. Psychologist Havelock Ellis (1859-1939) worried that even if homosexual men could bring themselves to engage in heterosexual intercourse, the underlying "perversion" would remain largely undisturbed. He called intercourse under these circumstances masturbation per vaginam.4

For his part, Freud thought of human beings as psychically bisexual by nature, as able to express erotic interest in both male and females. Freud saw exclusive homosexuality as a half-way phase between autoeroticism and mature sexuality.5 Even so, he thought of some men and women as congenitally disposed to homosexuality, not that he thought psychoanalysis could go much beyond that conclusion: "It is not for psychoanalysis to solve the problem of homosexuality. It must rest content with disclosing the psychical mechanisms that resulted in determining the object choice, and with track back the paths from them to instinctual dispositions."6 In the end, Freud was skeptical about sexual reorientation, but did not rule it out altogether.

The theory that homosexuality is genetic-and therefore inborn in at least some people-was resisted by certain psychologists and clinicians who were unwilling to give up the idea of therapy. In 1957, a British government committee issued The Wolfenden Report, which declared that homosexuality was not itself evidence of a disease and which recommended decriminalizing homosexuality among adults. In 1963, psychiatrist William Menninger wrote a forward to a copy of that report published in the United States. Contrary to the spirit of the Report, he noted that homosexuality ranks high in the kingdom of evils. He said, "Whatever it be called by the public, there is no question in the minds of psychiatrists regarding the abnormality of such behavior."7 He thought there were ways to re-educate and rehabilitate homosexual men and women, and he called on medicine to rise to the challenge of restoring heterosexuality to all men and women.

Gradually, however, genetic researchers challenged the dominance of psychological accounts of homosexuality. In the early 1950s, psychiatrist Franz J. Kallman carried out the first studies of homosexuality in twins.8 Kallman looked at 95 cases of twin brothers and found that among the dizygotic twins, 60% showed no evidence of homosexuality, while 11.5% exhibited a homosexual orientation meriting a 5 or 6 rating on the Kinsey scale ("predominantly" or "exclusively homosexual"), making both brothers more or less exclusively homosexual. By contrast, among monozygotic twins, Kallman reported a 100% concordance: if one brother was homosexual so was the other. Not only that but "most of the one-egg pairs tend to be similar in the role they take in their individualized sex activities, as well as in the extent of feminized appearance and behavior." He concluded that there was a "gene controlled disarrangement in the balance between male and female . . . tendencies."

Kallman's method of subject selection biased his results, and his interpretation of the data fails to account for other factors that might contribute to a sexual orientation shared by twins, such as shared developmental environments. Later studies would also indicate that monozygotic twins might share a homosexual orientation in common more frequently than with other brothers, but none of these studies-and there have only been a handful-indicate that genetics are entirely decisive.

The idea that homosexuality is genetic or in some other way involuntary certainly did not put an end to sexual orientation therapy. Some therapists specifically rejected the idea that homosexuality was genetic. While this kept the door open to psychological "therapies," it did sometimes have the beneficial effect of casting castration and hormonal injections into doubt as treatment options. Other therapists held that homosexuality could be altered in spite of a biological origin. For example, in 1970, J.N. Marquis advocated the use of "orgasmic reconditioning" to change sexual orientation. In that therapy, a homosexual client would be advised to masturbate according to his usual fantasies and imagery of males, but at the moment of climax switch to female fantasies and imagery. In theory, sexual orientation would follow where pleasure led it.

In puzzling over the origins of homosexuality, clinicians and researchers have rounded up the usual suspects when it comes to explaining human traits: genetics, early biological events, and psychological development. Genetics is a seductive siren in this regard, since it deals with organisms at their lowest level of causality. From time to time, contemporary genetics studies of homosexuality appear and ping-pong their way through the media; but none have accounted for human sexual orientation in any definitive way, and if the past is a prologue to the future, neither will they entirely extinguish the idea that sexual orientation is immutable. What has really killed most interest in sexual orientation therapy is not proof of the genetic origins of homosexuality, but the rejection of the notion that homosexuality is a condition that needs to be "cured." If we wish to promote social equality for gay men and lesbians, the origins of their sexual identities is beside the point.


Timothy F. Murphy holds a doctorate in philosophy from Boston College and is Professor of Philosophy in the Biomedical Sciences at the University of Illinois College of Medicine at Chicago. He is the author of Gay Science: The Ethics of Sexual Orientation Research (Columbia University Press), and in 2012, The MIT Press will publish his next book, Ethics, Sexual Orientation, and Choices about Children.


1. Meagher, John F.W., Homosexuality: Its Psychobiological and Psychopathological Significance. Urologic and Cutaneous Review 1929(33) 8: 505-518; 508.
2. Krafft-Ebing, Richard von. Psychopathia Sexualis, with Special Reference to Contrary Sexual Instinct. Philadelphia: F.A. Davis Co., 1894 [originally 1886]., p. 228.
3. Anonymous, Sexual Anomalies: The Origins, Nature, and Treatment of Sexual Disorders. A summary of the Work of Magnus Hirschfeld (New York: Emerson, 1956), p. 236
4. Ellis, Havelock and John Addington Symonds, Sexual Inversion (New York: Arno Press, 1975 [originally 1897]), p. 143
5. Freud, Sigmund, “Psycho-analytic Notes on an Autobiographical Account of a Case of Paranoia (Dementia Paranoides),” Standard Edition of the Complete Psychological Works of Sigmund Freud, vol. XII, James Strachey ed. (London: Hogarth, 1958 [originally 1911]), p. 60.
6. Freud, Sigmund, “The Psychogenesis of a Case of Homosexuality in a Woman,” Standard Edition of the Complete Psychological Works of Sigmund Freud, vol. XVIII, James Strachey, ed. (London: Hogarth Press, 1955 [originally 1920]), pp. 145-172. p. 171. 
7. Committee on Homosexual Offenses and Prostitution, The Wolfenden Report (New York: Stein and Day, 1963), p. 6.
8. Kallmann, F. J., Heredity in Health and Mental Disorder: Principles of Psychiatric Genetics in the Light of Comparative Twin Studies (New York: Norton, 1953), pp 116-119.

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The Gene Myths series features incisive, succinct articles by leading scientists disputing the exaggerations and misrepresentations of the power of genes.
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