Look down at your right hand. Is your ring finger longer than your index finger? Or vice versa? To be certain, take a ruler and measure from the bottom crease of each finger to the tip.
The measurements tell you something about the environment of your mother's womb just weeks after your conception, a time when your fingers, and more importantly, your brain, were developing. Because of the influx of sex hormones at this prenatal stage, men tend to have ring fingers that are slightly longer than their index fingers. In women, these fingers are usually the same length or the index digit is just a bit longer.
Digits are subtly affected by testosterone and estrogen produced in the womb by the fetus (not by the mother). Between weeks 8 and 14, tiny fetal testes, ovaries and adrenal glands secrete the baby's own supply of sex hormones. These chemical messengers, particularly testosterone, cause chain reactions in the body, spurring the growth of the genitals, encouraging and inhibiting growth in brain regions and causing changes in the fingers. Many scientists believe relative finger length—or digit ratio—is a marker for brain differences molded by hormones. Like a bit of prenatal graffiti, a longer ring finger says, "Testosterone was here."
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Some scientists believe prenatal sex hormones are also part of the puzzle of homosexuality and that a high level of testosterone may wire the brain for attraction to the same sex. Intriguingly, research shows that a prenatal testosterone level is most strongly linked to homosexuality in women, according to a recent article in the Archives of Sexual Behavior. Lesbians are more likely than straight women to have a masculine finger ratio, says McFadden.
http://cms.psychologytoday.com/articles/pto-20050614-000004.html