Homosexual men have a higher mean birth order than do heterosexual men, primarily because they have a greater number of older brothers.
The purpose of this study was to determine whether the same difference occurs in homosexual vs heterosexual women.
The probands were 964 homosexual and heterosexual male and female volunteers, from whom birth order data were collected with self-administered questionnaires.
The homosexual men had more older brothers than the heterosexual men, but they did not have more older sisters, younger brothers, or younger sisters.
The homosexual women did not differ from the heterosexual women with regard to any class of sibling, These results are consistent with the hypothesis that the high birth order of homosexual men reflects the progressive immunization of certain mothers to H-Y antigen by succeeding male fetuses, and the increasing effects of H-Y antibodies on sexual differentiation of the brain in succeeding male fetuses.
Mots-clés Pascal : Homosexualité, Hétérosexualité, Comportement sexuel, Rang naissance, Epidémiologie, Facteur risque, Homme, Femelle, Mâle, Etats Unis, Amérique du Nord, Amérique, Angleterre, Grande Bretagne, Royaume Uni, Europe
Mots-clés Pascal anglais : Homosexuality, Heterosexuality, Sexual behavior, Birth order, Epidemiology, Risk factor, Human, Female, Male, United States, North America, America, England, Great Britain, United Kingdom, Europe
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 98-0510993
Code Inist : 002A26G05. Création : 23/03/1999.