Lalumière et al., 2000 meta-analysis Lalumière
et al. conducted a
meta-analysis of 20 studies with a total of 6,987 homosexual and 16,423 heterosexual participants. They found that homosexual men had a 34% greater odds of not being right-handed, and homosexual women had a 91% greater odds (39% overall).
Williams et al., 2000 In a study involving 382 men (278 homosexual and 104 heterosexual) no significant association emerged between handedness and sexual orientation.
Mustanski et al., 2002 study Mustanski
et al. examined sexual orientation and hand preference in a sample of 382 men (205 heterosexual; 177 homosexual) and 354 women (149 heterosexual; 205 homosexual). Although a significantly higher proportion of
homosexual women was found to be left-handed compared to heterosexual women (18% vs. 10%), no significant differences were found between heterosexual and homosexual men with respect to hand preference.
Blanchard et al., 2006 study Blanchard
et al. argued that the
fraternal birth order effect (the probability that a boy will be homosexual increases with the number of older brothers who have the same biological mother) appears to be limited to right-handed men. Moreover, the same study indicates that left-handed men without older brothers are more likely to be homosexual than non-right-handed men who have older brothers.
BBC survey In a multinational online survey, it was found that
gay men and lesbians are more likely to be left-handed (13 and 11%, respectively) than heterosexual men and women (11% and 10%, respectively). Bisexuals of both sexes more often described themselves as ambidextrous than gay or heterosexual individuals of the same sex (bisexual men: 12%; gay and heterosexual men: 8%; bisexual women: 16%; lesbians: 12%; heterosexual women: 8%).
Blanchard, 2008 Archives of Sexual Behavior study A subsequent study by Blanchard found that both right-handed homosexual men and left-handed heterosexual men had a statistically significant number of older male siblings, but that there was no significant observable effect either for right-handed heterosexual men or for left-handed homosexual men.
Blanchard, 2008 Laterality study Blanchard discussed ways in which the
fraternal birth order effect and handedness could be explained in terms of the maternal immune hypothesis. In this, the mother is assumed to grow more immune to male
antigens with each pregnancy, and thus produce a greater number of "anti-male"
antibodies. He suggests two possibilities: Either that non-right-handed fetuses are less sensitive to the antibodies, or that the mothers of left-handed fetuses do not, for some reason, produce them.
Schwartz et al., 2010 hair whorl study In a sample including 694 gay men and 894 straight men, it was found that 13.9% of gay men and 15.9% of straight men were not right-handed, a non-significant difference. The study replicated the 'older brother effect' for homosexual men, but unlike Blanchard (2006) (see above), it found that the effect applied to both right-handed and left-handed gay men, being in effect stronger for the latter than for the former.
Kishida and Rahman, 2015 In a sample of 478 heterosexual men and 425 homosexual men, gay men were found to show a significantly greater likelihood of extreme right-handedness and non-right-handedness compared to heterosexual men.
Lee Ellis et al., 2016 Among a sample of university students in
Malaysia and the
United States, it was found that same-sex attraction was linked with left-handedness among women. Among men, no such correlation was found after controlling for ethnicity.
Asexuality A 2014 Internet study attempted to analyze the relationship between self-identification as
asexual, handedness and other biological markers, in comparison to individuals of other sexual orientation groups. A total of 325 asexuals (60 men and 265 women), 690 heterosexuals (190 men and 500 women), and 268 non-heterosexuals (64 men and 204 women) completed online questionnaires. The study asserts that asexual men and women were 2.4 and 2.5 times, respectively, more likely to not be right-handed than their heterosexual counterparts. == See also ==