title: Fraternal Birth Order, Handedness, and Sexual Orientation in a Chinese Population.
abstract: We examined the relationship between handedness, fraternal birth order, and sexual orientation in a Chinese population, and analyzed the influence of the components assessing sexual orientation and criteria classifying individuals as homosexual on this relationship. A large sample of heterosexual, bisexual, and homosexual men and women participated in a web-based survey. Our results showed that homosexual women are more likely to be non-right-handed than heterosexual women, regardless of how sexual orientation was defined, whereas bisexual women are more likely to be non-right-handed than heterosexual women when sexual orientation was assessed via sexual attraction and sexual identity. Bisexual men are more likely to be non-right-handed than heterosexual men when sexual orientation was assessed via sexual attraction. We found neither a fraternal birth-order effect nor an interaction between sibling sex ratio, handedness, and sexual orientation. The small number of siblings may be the reason why we could not replicate the fraternal birth-order effect in this Chinese population, which highlights the importance of cultural differences in the understanding of handedness, fraternal birth order, and sexual orientation.
authors.affiliation: a School of Psychology , Southwest University , Chongqing , China.
authors.forename: Yin
authors.initials: Y
authors.lastname: Xu
authors.affiliation: a School of Psychology , Southwest University , Chongqing , China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zheng
mesh_terms: D000293:Adolescent; D000328:Adult; D001722:Birth Order; D001727:Bisexuality / Q000706:statistics & numerical data*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D020010:Heterosexuality / Q000706:statistics & numerical data*; D018452:Homosexuality, Female / Q000706:statistics & numerical data*; D018451:Homosexuality, Male / Q000706:statistics & numerical data*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult