I typed this up from a Popular Science magazine.
Researchers at the University of California-Berkeley have found more evidence to support the theory that exposure to varying levels of hormones in the womb affects sexual orientation.
After interviewing 720 people at local fairs in San Francisco and examining their hands, researchers led by Marc Breedlove found that homosexual women's ring fingers tend to be longer than their index fingers. The reason he suggests: They're exposed to more testoterone in the womb than heterosexual women are. Testoterone interacts with specific genes in a developing fetus and determines its sex. Other research as shown that the hormone also interacts with the genes responsible for directing the growth of fingers.
Breedlove came up with his streetside experment based on his studies of mice. "I can always make the animals more masculine or feminine by controlling the amount of testoterone they are exposes to before and after birth." A female mouse fetus exposed to more testoterone will exhibit male behavior patters, says Breedlove.
The study also found that men with two or three older male siblings were more likely to be gay. Breedlove suspects that after each successive male birth, the mother's body secretes increasingly more testosterone, which in turn affets each successive fetus.
Breedlove is cautious though, and adds that exposure to testosterone is not the only thing that can determine someone's sexual orientation. Genes, he says, likely play an even larger role. -- Christopher Miller
Researchers at the University of California-Berkeley have found more evidence to support the theory that exposure to varying levels of hormones in the womb affects sexual orientation.
After interviewing 720 people at local fairs in San Francisco and examining their hands, researchers led by Marc Breedlove found that homosexual women's ring fingers tend to be longer than their index fingers. The reason he suggests: They're exposed to more testoterone in the womb than heterosexual women are. Testoterone interacts with specific genes in a developing fetus and determines its sex. Other research as shown that the hormone also interacts with the genes responsible for directing the growth of fingers.
Breedlove came up with his streetside experment based on his studies of mice. "I can always make the animals more masculine or feminine by controlling the amount of testoterone they are exposes to before and after birth." A female mouse fetus exposed to more testoterone will exhibit male behavior patters, says Breedlove.
The study also found that men with two or three older male siblings were more likely to be gay. Breedlove suspects that after each successive male birth, the mother's body secretes increasingly more testosterone, which in turn affets each successive fetus.
Breedlove is cautious though, and adds that exposure to testosterone is not the only thing that can determine someone's sexual orientation. Genes, he says, likely play an even larger role. -- Christopher Miller
Facebook
Twitter