Handedness, sexual orientation, and gender-related personality traits in men and women.

This study assessed large numbers of heterosexual and homosexual men and women on handedness and gender-related personality traits. Initial analyses employed a dichotomous measure of handedness (right-handed vs. non-right-handed). For men and women combined, homosexual participants had 50% greater odds of being non-right-handed than heterosexual participants, a statistically significant difference. Homosexual men had 82% greater odds of being non-right-handed than heterosexual men, a statistically significant difference, whereas homosexual women had 22% greater odds of being non-right-handed than heterosexual women, a nonsignificant difference. When participants were classified into five graduated categories of handedness, both men and women showed significant homosexual-heterosexual differences in handedness distributions. Within groups, handedness showed a number of weak but statistically significant associations with sex-typed occupational preferences, self-ascribed masculinity, and self-ascribed femininity, but not with instrumentality or expressiveness. Rates of non-right-handedness were virtually identical for heterosexual men and women, suggesting that sex differences in handedness may result from higher rates of homosexuality in men.