Skip to main content Accessibility help

A Male Monozygotic Twinship Discordant for Homosexuality: A Repertory Grid Study

  • K. Davison (a1), H. Brierley (a1) and C. Smith (a1)


The relative contribution of genetic and environmental factors to the development of homosexual behaviour is a controversial subject. The original suggestion that homosexuality is a purely inherited trait has been attributed to Krafft-Ebing (Kallmann, 1952). Perhaps the strongest support for this view was Kallmann's series of 40 male monozygotic twin pairs showing 100 per cent concordance for the overt practice and quantitative rating of homosexual behaviour (Kallmann, 1952). This report has been criticized, and Kallmann later conceded that the 100 per cent concordance was possibly a statistical artefact (Kallmann, 1960). Habel (1950), who obtained the index twins from a prison population, found concordant homosexuality in 3 out of 5 monozygotic pairs (60 per cent), but none of 5 dizygotic pairs. In a more recent study, Heston and Shields (1968) found concordant homosexuality in 2 out of 5 monozygotic pairs (40 per cent) and 1 out of 7 dizygotic pairs (14 per cent). Heston and Shields (1968) also report a family with a sibship of 14 which included 3 pairs of male monozygotic twins, in two of which both twins were homosexual and in the third both heterosexual; no environmental factors which differentiated the homosexual from the heterosexual sibs could be detected. These workers also refute the suggestion that the tendency for monozygotic twins to be more alike with regard to homosexuality than dizygotic twins is related not to genetic factors but to problems of sexual identification which predispose to homosexuality (Money, 1962) by pointing out that there is no evidence that monozygotic twins per se are especially prone to become homosexual.



Hide All
Bene, E. (1965). ‘On the genesis of male homosexuality.’ British Journal of Psychiatry, 111, 803–13.
Bieber, I., Dain, H. J., Dince, P. R., Drellich, M. G., Grand, H. G., Gundloch, R. H., Kremer, M. W., Rifkin, A. H., Wilbur, C. B., and Bieber, T. B. (1962). Homosexuality. New York. Basic Books.
Brown, D. G. (1958). ‘Sex-rôle development in a changing culture.’ Psychological Bulletin, 54, 232–42.
Brown, D. G. (1963). ‘Homosexuality and family dynamics.’ Bulletin of the Menninger Clinic, 27, 227–32.
Fenichel, O. (1945). The Psychoanalytical Theory of Neurosis. New York: Norton.
Freud, S. (1910). Three Essays on the Theory of Sexuality. I The Sexual Aberration, p. 19. (transl. Strachey, J. 1949). London: Imago.
Habel, H. (1950). ‘Zwillingsuntersuchungen an Homo-sexuellen.’ Zeitschrifl für Sexualforschung. 1, 161–80.
Heston, L. L., and Shields, J. (1968). ‘Homosexuality in twins. A family study and a registry study.’ Archives of General Psychiatry, 18, 149–60.
Kallmann, F. J. (1952). ‘Comparative twin study on the genetic aspects of male homosexuality.’ Journal of Nervous and Mental Disease, 115, 283–98.
Kallmann, F. J. (1960), discussion p. 259 of Rainer et al. (1960).
Klintworth, G. K. (1962). ‘A pair of male monozygotic twins discordant for homosexuality.’ Journal of Nervous and Mental Disease, 135, 113–25.
Lange, J. (1930). Crime as Destiny: A Study of Criminial Twins. Pp. 154–60. London: Allen and Unwin.
Mesnikoff, A. M., Rainer, J. D., Kolb, L. C., and Garr, A. C. (1963). ‘Intra-familial determinants of divergent sexual behaviour in twins.’ American Journal of Psychiatry, 119, 732–8.
Money, J. (1962). ‘Factors in the Genesis of Homosexuality’ in Determinants of Sexual Behaviour (Ed. G. Winokur), Springfield, Illinois: C.C.Thomas.
O'Connor, P. J. (1964). ‘Aetiological factors in homosexuality as seen in RAF practice.’ British Journal of Psychiatry, 110, 381–91.
Parker, N. (1964). ‘Homosexuality in twins: A report on three discordant pairs.’ British Journal of Psychiatry, 111, 489–95.
Rainer, J. D., Mesnikoff, A., Kolb, L. C., and Carr, A. (1960). ‘Homosexuality and heterosexuality in identical twins.’ Psychosomatic Medicine, 22, 251–9.
Sanders, J. (1934). ‘Homosexueele tweelingen.’ Nederlandsch Tijdschrift voor de Geneeskunde, 78, 3346–52.
Slater, E. (1963). ‘Diagnosis of zygosity by fingerprints.’ Acta Psychiatrica Scandinavica, 39, 7884.
Slater, P. (1964). The Principal Components of a Repertory Grid. London: Vincent Andrew and Co.
Slater, P. (1965). ‘The use of the repertory grid technique in the individual case.’ British Journal of Psychiatry, 111, 965–75.
Smith, S. M., and Penrose, L. S. (1955). ‘Monozygotic and dizygotic twin diagnosis.’ Annals of Human Genetics, 19, 273–89.
Tanner, J. M. (1951). ‘Photogrammctric anthropometry and an androgyny scale.’ Lancet, i, 574–9.
West, D. J. (1959). ‘Parental figures in the genesis of male homosexuality.’ International Journal of Social Psychiatry, 5, 8597.

A Male Monozygotic Twinship Discordant for Homosexuality: A Repertory Grid Study

  • K. Davison (a1), H. Brierley (a1) and C. Smith (a1)


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed

A Male Monozygotic Twinship Discordant for Homosexuality: A Repertory Grid Study

  • K. Davison (a1), H. Brierley (a1) and C. Smith (a1)
Submit a response


No eLetters have been published for this article.


Reply to: Submit a response

Your details

Conflicting interests

Do you have any conflicting interests? *