易性癖和左利手也许具有共同起源(上)
NEW YORK, Nov 16 (Reuters Health) - Left-handedness may be more common among transsexuals than in the general population, suggesting that the two conditions might share a common developmental origin, according to UK researchers.
"Both male and female transsexuals were more often non-right-handed" compared with non-transsexual males or females, according to Dr. Richard Green and Robert Young of Charing Cross Hospital in London.
Some researchers believe that handedness may be determined by prenatal exposure to male hormones, or androgens, in the womb. Green and Young note that a fetal preference for one hand over the other "has been observed as early as week 15 of gestation." One theory is that this hormonal exposure influences the structural development of the brain, which later helps determine which hand a person favors.
Similarly, according to the British authors, many experts speculate that homosexuality is linked to androgen exposure during fetal development. And past research has suggested that structural differences between the brains of men and women, as well as homosexual and heterosexual men, may occur early in brain development.
All of this speculation has triggered "considerable recent attention" to the possible link between handedness and sexual orientation, Green and Young note in the December issue of Archives of Sexual Behavior.
Their study of 443 male-to-female transsexuals and 93 female-to-male transsexuals showed that these individuals were less likely to be exclusively right-handed compared with a "control" group of 284 volunteers., 百拇医药
"Both male and female transsexuals were more often non-right-handed" compared with non-transsexual males or females, according to Dr. Richard Green and Robert Young of Charing Cross Hospital in London.
Some researchers believe that handedness may be determined by prenatal exposure to male hormones, or androgens, in the womb. Green and Young note that a fetal preference for one hand over the other "has been observed as early as week 15 of gestation." One theory is that this hormonal exposure influences the structural development of the brain, which later helps determine which hand a person favors.
Similarly, according to the British authors, many experts speculate that homosexuality is linked to androgen exposure during fetal development. And past research has suggested that structural differences between the brains of men and women, as well as homosexual and heterosexual men, may occur early in brain development.
All of this speculation has triggered "considerable recent attention" to the possible link between handedness and sexual orientation, Green and Young note in the December issue of Archives of Sexual Behavior.
Their study of 443 male-to-female transsexuals and 93 female-to-male transsexuals showed that these individuals were less likely to be exclusively right-handed compared with a "control" group of 284 volunteers., 百拇医药